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Network Working Group                                T. Hastings, EditorRequest for Comments: 2911                                    R. HerriotObsoletes:2566                                        Xerox CorporationCategory: Standards Track                                       R. deBry                                               Utah Valley State College                                                             S. Isaacson                                                            Novell, Inc.                                                               P. Powell                                                     Astart Technologies                                                          September 2000Internet Printing Protocol/1.1: Model and SemanticsStatus of this Memo   This document specifies an Internet standards track protocol for the   Internet community, and requests discussion and suggestions for   improvements.  Please refer to the current edition of the "Internet   Official Protocol Standards" (STD 1) for the standardization state   and status of this protocol.  Distribution of this memo is unlimited.Copyright Notice   Copyright (C) The Internet Society (2000).  All Rights Reserved.Abstract   This document is one of a set of documents, which together describe   all aspects of a new Internet Printing Protocol (IPP).  IPP is an   application level protocol that can be used for distributed printing   using Internet tools and technologies.  This document describes a   simplified model consisting of abstract objects, their attributes,   and their operations that is independent of encoding and transport.   The model consists of a Printer and a Job object.  A Job optionally   supports multiple documents.  IPP 1.1 semantics allow end-users and   operators to query printer capabilities, submit print jobs, inquire   about the status of print jobs and printers, cancel, hold, release,   and restart print jobs.  IPP 1.1 semantics allow operators to pause,   resume, and purge (jobs from) Printer objects.  This document also   addresses security, internationalization, and directory issues.Hastings, et al.            Standards Track                     [Page 1]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The full set of IPP documents includes:     Design Goals for an Internet Printing Protocol [RFC2567]     Rationale for the Structure and Model and Protocol for the Internet     Printing Protocol [RFC2568]     Internet Printing Protocol/1.1: Model and Semantics (this document)     Internet Printing Protocol/1.1: Encoding and Transport [RFC2910]     Internet Printing Protocol/1.1: Implementer's Guide [IPP-IIG]     Mapping between LPD and IPP Protocols [RFC2569]   The "Design Goals for an Internet Printing Protocol" document takes a   broad look at distributed printing functionality, and it enumerates   real-life scenarios that help to clarify the features that need to be   included in a printing protocol for the Internet.  It identifies   requirements for three types of users: end users, operators, and   administrators.  It calls out a subset of end user requirements that   are satisfied in IPP/1.0.  A few OPTIONAL operator operations have   been added to IPP/1.1.   The "Rationale for the Structure and Model and Protocol for the   Internet Printing Protocol" document describes IPP from a high level   view, defines a roadmap for the various documents that form the suite   of IPP specification documents, and gives background and rationale   for the IETF working group's major decisions.   The "Internet Printing Protocol/1.1: Encoding and Transport" document   is a formal mapping of the abstract operations and attributes defined   in the model document onto HTTP/1.1 [RFC2616].  It defines the   encoding rules for a new Internet MIME media type called   "application/ipp".  This document also defines the rules for   transporting over HTTP a message body whose Content-Type is   "application/ipp".  This document defines a new scheme named 'ipp'   for identifying IPP printers and jobs.   The "Internet Printing Protocol/1.1: Implementer's Guide" document   gives insight and advice to implementers of IPP clients and IPP   objects.  It is intended to help them understand IPP/1.1 and some of   the considerations that may assist them in the design of their client   and/or IPP object implementations.  For example, a typical order of   processing requests is given, including error checking.  Motivation   for some of the specification decisions is also included.   The "Mapping between LPD and IPP Protocols" document gives some   advice to implementers of gateways between IPP and LPD (Line Printer   Daemon) implementations.Hastings, et al.            Standards Track                     [Page 2]

RFC 2911              IPP/1.1: Model and Semantics        September 2000Table of Contents   1.   Introduction                                                 9   1.1   Simplified Printing Model                                  10   2.   IPP Objects                                                 12   2.1   Printer Object                                             13   2.2   Job Object                                                 15   2.3   Object Relationships                                       16   2.4   Object Identity                                            17   3.   IPP Operations                                              20   3.1   Common Semantics                                           21   3.1.1  Required Parameters                                       21   3.1.2  Operation IDs and Request IDs                             22   3.1.3  Attributes                                                22   3.1.4  Character Set and Natural Language Operation Attribute    24   3.1.4.1   Request Operation Attributes                           25   3.1.4.2   Response Operation Attributes                          29   3.1.5  Operation Targets                                         30   3.1.6  Operation Response Status Codes and Status Messages       32   3.1.6.1   "status-code" (type2 enum)                             32   3.1.6.2   "status-message" (text(255))                           33   3.1.6.3   "detailed-status-message" (text(MAX))                  33   3.1.6.4   "document-access-error" (text(MAX))                    34   3.1.7  Unsupported Attributes                                    34   3.1.8  Versions                                                  36   3.1.9  Job Creation Operations                                   38   3.2   Printer Operations                                         41   3.2.1  Print-Job Operation                                       41   3.2.1.1   Print-Job Request                                      41   3.2.1.2   Print-Job Response                                     46   3.2.2  Print-URI Operation                                       48   3.2.3  Validate-Job Operation                                    49   3.2.4  Create-Job Operation                                      49   3.2.5  Get-Printer-Attributes Operation                          50   3.2.5.1   Get-Printer-Attributes Request                         51   3.2.5.2   Get-Printer-Attributes Response                        53   3.2.6  Get-Jobs Operation                                        54   3.2.6.1   Get-Jobs Request                                       54   3.2.6.2   Get-Jobs Response                                      56   3.2.7  Pause-Printer Operation                                   57   3.2.7.1   Pause-Printer Request                                  59   3.2.7.2   Pause-Printer Response                                 60   3.2.8  Resume-Printer Operation                                  60   3.2.9  Purge-Jobs Operation                                      61   3.3   Job Operations                                             62   3.3.1  Send-Document Operation                                   62   3.3.1.1   Send-Document Request                                  64   3.3.1.2   Send-Document Response                                 65Hastings, et al.            Standards Track                     [Page 3]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   3.3.2  Send-URI Operation                                        66   3.3.3  Cancel-Job Operation                                      66   3.3.3.1   Cancel-Job Request                                     67   3.3.3.2   Cancel-Job Response                                    68   3.3.4  Get-Job-Attributes Operation                              69   3.3.4.1   Get-Job-Attributes Request                             69   3.3.4.2   Get-Job-Attributes Response                            70   3.3.5  Hold-Job Operation                                        71   3.3.5.1   Hold-Job Request                                       72   3.3.5.2   Hold-Job Response                                      73   3.3.6  Release-Job Operation                                     74   3.3.7  Restart-Job Operation                                     75   3.3.7.1   Restart-Job Request                                    76   3.3.7.2   Restart-Job Response                                   78   4.   Object Attributes                                           78   4.1   Attribute Syntaxes                                         78   4.1.1  'text'                                                    79   4.1.1.1   'textWithoutLanguage'                                  80   4.1.1.2   'textWithLanguage'                                     80   4.1.2  'name'                                                    81   4.1.2.1   'nameWithoutLanguage'                                  82   4.1.2.2   'nameWithLanguage'                                     82   4.1.2.3   Matching 'name' attribute values                       83   4.1.3  'keyword'                                                 84   4.1.4  'enum'                                                    85   4.1.5  'uri'                                                     85   4.1.6  'uriScheme'                                               86   4.1.7  'charset'                                                 86   4.1.8  'naturalLanguage'                                         87   4.1.9  'mimeMediaType'                                           87   4.1.9.1 Application/octet-stream -- Auto-Sensing                 88           the document format   4.1.10 'octetString'                                             89   4.1.11 'boolean'                                                 89   4.1.12 'integer'                                                 89   4.1.13 'rangeOfInteger'                                          90   4.1.14 'dateTime'                                                90   4.1.15 'resolution'                                              90   4.1.16 '1setOf  X'                                               90   4.2   Job Template Attributes                                    91   4.2.1  job-priority (integer(1:100))                             94   4.2.2  job-hold-until (type3 keyword | name (MAX))               95   4.2.3  job-sheets (type3 keyword | name(MAX))                    96   4.2.4  multiple-document-handling (type2 keyword)                96   4.2.5  copies (integer(1:MAX))                                   98   4.2.6  finishings (1setOf type2 enum)                            98   4.2.7  page-ranges (1setOf rangeOfInteger (1:MAX))              101   4.2.8  sides (type2 keyword)                                    102Hastings, et al.            Standards Track                     [Page 4]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   4.2.9  number-up (integer(1:MAX))                               102   4.2.10 orientation-requested (type2 enum)                       103   4.2.11 media (type3 keyword | name(MAX))                        104   4.2.12 printer-resolution (resolution)                          105   4.2.13 print-quality (type2 enum)                               105   4.3   Job Description Attributes                                106   4.3.1  job-uri (uri)                                            107   4.3.2  job-id (integer(1:MAX))                                  108   4.3.3  job-printer-uri (uri)                                    108   4.3.4  job-more-info (uri)                                      108   4.3.5  job-name (name(MAX))                                     108   4.3.6  job-originating-user-name (name(MAX))                    109   4.3.7  job-state (type1 enum)                                   109   4.3.7.1   Forwarding Servers                                    112   4.3.7.2   Partitioning of Job States                            112   4.3.8  job-state-reasons (1setOf  type2 keyword)                113   4.3.9  job-state-message (text(MAX))                            118   4.3.10 job-detailed-status-messages (1setOf text(MAX))          118   4.3.11 job-document-access-errors (1setOf text(MAX))            118   4.3.12 number-of-documents (integer(0:MAX))                     119   4.3.13 output-device-assigned (name(127))                       119   4.3.14 Event Time Job Description Attributes                    119   4.3.14.1  time-at-creation (integer(MIN:MAX))                   120   4.3.14.2  time-at-processing (integer(MIN:MAX))                 120   4.3.14.3  time-at-completed (integer(MIN:MAX))                  120   4.3.14.4  job-printer-up-time (integer(1:MAX))                  120   4.3.14.5  date-time-at-creation (dateTime)                      121   4.3.14.6  date-time-at-processing (dateTime)                    121   4.3.14.7  date-time-at-completed (dateTime)                     121   4.3.15 number-of-intervening-jobs (integer(0:MAX))              121   4.3.16 job-message-from-operator (text(127))                    121   4.3.17 Job Size Attributes                                      121   4.3.17.1  job-k-octets (integer(0:MAX))                         122   4.3.17.2  job-impressions (integer(0:MAX))                      122   4.3.17.3  job-media-sheets (integer(0:MAX))                     123   4.3.18 Job Progress Attributes                                  123   4.3.18.1  job-k-octets-processed (integer(0:MAX))               123   4.3.18.2  job-impressions-completed (integer(0:MAX))            123   4.3.18.3  job-media-sheets-completed (integer(0:MAX))           124   4.3.19 attributes-charset (charset)                             124   4.3.20 attributes-natural-language (naturalLanguage)            124   4.4   Printer Description Attributes                            124   4.4.1  printer-uri-supported (1setOf uri)                       126   4.4.2  uri-authentication-supported (1setOf type2 keyword)      127   4.4.3  uri-security-supported (1setOf type2 keyword)            128   4.4.4  printer-name (name(127))                                 129   4.4.5  printer-location (text(127))                             129   4.4.6  printer-info (text(127))                                 130Hastings, et al.            Standards Track                     [Page 5]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   4.4.7  printer-more-info (uri)                                  130   4.4.8  printer-driver-installer (uri)                           130   4.4.9  printer-make-and-model (text(127))                       130   4.4.10 printer-more-info-manufacturer (uri)                     130   4.4.11 printer-state (type1 enum)                               131   4.4.12 printer-state-reasons (1setOf type2 keyword)             131   4.4.13 printer-state-message (text(MAX))                        134   4.4.14 ipp-versions-supported (1setOf type2 keyword)            134   4.4.15 operations-supported (1setOf type2 enum)                 135   4.4.16 multiple-document-jobs-supported (boolean)               136   4.4.17 charset-configured (charset)                             136   4.4.18 charset-supported (1setOf charset)                       137   4.4.19 natural-language-configured (naturalLanguage)            137   4.4.20 generated-natural-language-supported          (1setOf naturalLanguage)                                 137   4.4.21 document-format-default (mimeMediaType)                  138   4.4.22 document-format-supported (1setOf mimeMediaType)         138   4.4.23 printer-is-accepting-jobs (boolean)                      138   4.4.24 queued-job-count (integer(0:MAX))                        138   4.4.25 printer-message-from-operator (text(127))                139   4.4.26 color-supported (boolean)                                139   4.4.27 reference-uri-schemes-supported (1setOf uriScheme)       139   4.4.28 pdl-override-supported (type2 keyword)                   139   4.4.29 printer-up-time (integer(1:MAX))                         140   4.4.30 printer-current-time (dateTime)                          140   4.4.31 multiple-operation-time-out (integer(1:MAX))             141   4.4.32 compression-supported (1setOf type3 keyword)             141   4.4.33 job-k-octets-supported (rangeOfInteger(0:MAX))           142   4.4.34 job-impressions-supported (rangeOfInteger(0:MAX))        142   4.4.35 job-media-sheets-supported (rangeOfInteger(0:MAX))       142   4.4.36 pages-per-minute (integer(0:MAX))                        142   4.4.37 pages-per-minute-color (integer(0:MAX))                  142   5.   Conformance                                                143   5.1   Client Conformance Requirements                           143   5.2   IPP Object Conformance Requirements                       145   5.2.1  Objects                                                  145   5.2.2  Operations                                               145   5.2.3  IPP Object Attributes                                    146   5.2.4  Versions                                                 146   5.2.5  Extensions                                               147   5.2.6  Attribute Syntaxes                                       147   5.2.7  Security                                                 148   5.3   Charset and Natural Language Requirements                 148   6.   IANA Considerations                                        148   6.1   Typed 'keyword' and 'enum' Extensions                     149   6.2   Attribute Extensibility                                   151   6.3   Attribute Syntax Extensibility                            152   6.4   Operation Extensibility                                   152Hastings, et al.            Standards Track                     [Page 6]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   6.5   Attribute Group Extensibility                             153   6.6   Status Code Extensibility                                 153   6.7   Out-of-band Attribute Value Extensibility                 154   6.8   Registration of MIME types/sub-types for document-formats 154   6.9   Registration of charsets for use in 'charset'         attribute values                                          154   7.   Internationalization Considerations                        154   8.   Security Considerations                                    158   8.1   Security Scenarios                                        159   8.1.1  Client and Server in the Same Security Domain            159   8.1.2  Client and Server in Different Security Domains          159   8.1.3  Print by Reference                                       160   8.2   URIs in Operation, Job, and Printer attributes            160   8.3   URIs for each authentication mechanisms                   160   8.4   Restricted Queries                                        161   8.5   Operations performed by operators and system         administrators                                            161   8.6   Queries on jobs submitted using non-IPP protocols         162   9.   References                                                 162   10.  Authors' Addresses                                         166   11.  Formats for IPP Registration Proposals                     168   11.1  Type2 keyword attribute values registration               169   11.2  Type3 keyword attribute values registration               169   11.3  Type2 enum attribute values registration                  169   11.4  Type3 enum attribute values registration                  170   11.5  Attribute registration                                    170   11.6  Attribute Syntax registration                             171   11.7  Operation registration                                    171   11.8  Attribute Group registration                              171   11.9  Status code registration                                  172   11.10 Out-of-band Attribute Value registration                  172   12.  APPENDIX A: Terminology                                    173   12.1  Conformance Terminology                                   173   12.1.1 NEED NOT                                                 173   12.2  Model Terminology                                         173   12.2.1 Keyword                                                  173   12.2.2 Attributes                                               173   12.2.2.1  Attribute Name                                        173   12.2.2.2  Attribute Group Name                                  174   12.2.2.3  Attribute Value                                       174   12.2.2.4  Attribute Syntax                                      174   12.2.3 Supports                                                 174   12.2.4 print-stream page                                        176   12.2.5 impression                                               177   13. APPENDIX B: Status Codes and Suggested Status Code Messages 177   13.1  Status Codes                                              178   13.1.1 Informational                                            178   13.1.2 Successful Status Codes                                  178Hastings, et al.            Standards Track                     [Page 7]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   13.1.2.1  successful-ok (0x0000)                                178   13.1.2.2  successful-ok-ignored-or-substituted-attributes             (0x0001)                                              179   13.1.2.3  successful-ok-conflicting-attributes (0x0002)         179   13.1.3 Redirection Status Codes                                 179   13.1.4 Client Error Status Codes                                179   13.1.4.1  client-error-bad-request (0x0400)                     180   13.1.4.2  client-error-forbidden (0x0401)                       180   13.1.4.3  client-error-not-authenticated (0x0402)               180   13.1.4.4  client-error-not-authorized (0x0403)                  180   13.1.4.5  client-error-not-possible (0x0404)                    180   13.1.4.6  client-error-timeout (0x0405)                         181   13.1.4.7  client-error-not-found (0x0406)                       181   13.1.4.8  client-error-gone (0x0407)                            181   13.1.4.9  client-error-request-entity-too-large (0x0408)        182   13.1.4.10 client-error-request-value-too-long (0x0409)          182   13.1.4.11 client-error-document-format-not-supported (0x040A)   182   13.1.4.12 client-error-attributes-or-values-not-supported             (0x040B)                                              183   13.1.4.13 client-error-uri-scheme-not-supported (0x040C)        183   13.1.4.14 client-error-charset-not-supported (0x040D)           183   13.1.4.15 client-error-conflicting-attributes (0x040E)          183   13.1.4.16 client-error-compression-not-supported (0x040F)       184   13.1.4.17 client-error-compression-error (0x0410)               184   13.1.4.18 client-error-document-format-error (0x0411)           184   13.1.4.19 client-error-document-access-error (0x0412)           184   13.1.5    Server Error Status Codes                             185   13.1.5.1  server-error-internal-error (0x0500)                  185   13.1.5.2  server-error-operation-not-supported (0x0501)         185   13.1.5.3  server-error-service-unavailable (0x0502)             185   13.1.5.4  server-error-version-not-supported (0x0503)           185   13.1.5.5  server-error-device-error (0x0504)                    186   13.1.5.6  server-error-temporary-error (0x0505)                 186   13.1.5.7  server-error-not-accepting-jobs (0x0506)              187   13.1.5.8  server-error-busy (0x0507)                            187   13.1.5.9  server-error-job-canceled (0x0508)                    187   13.1.5.10 server-error-multiple-document-jobs-not-supported             (0x0509)                                              187   13.2  Status Codes for IPP Operations                           187   14.  APPENDIX C:  "media" keyword values                        190   15.  APPENDIX D: Processing IPP Attributes                      208   15.1  Fidelity                                                  209   15.2  Page Description Language (PDL) Override                  210   15.3  Using Job Template Attributes During Document Processing  212   16.  APPENDIX E: Generic Directory Schema                       214   17.  APPENDIX F:  Differences between the IPP/1.0 and IPP/1.1        "Model and Semantics" Documents                            215   18.  Full Copyright Statement                                   224Hastings, et al.            Standards Track                     [Page 8]

RFC 2911              IPP/1.1: Model and Semantics        September 20001. Introduction   The Internet Printing Protocol (IPP) is an application level protocol   that can be used for distributed printing using Internet tools and   technologies.  IPP version 1.1 (IPP/1.1) focuses primarily on end   user functionality with a few administrative operations included.   This document is just one of a suite of documents that fully define   IPP.  The full set of IPP documents includes:     Design Goals for an Internet Printing Protocol [RFC2567]     Rationale for the Structure and Model and Protocol for the Internet     Printing Protocol [RFC2568]     Internet Printing Protocol/1.1: Model and Semantics (this document)     Internet Printing Protocol/1.1: Encoding and Transport [RFC2910]     Internet Printing Protocol/1.1: Implementer's Guide [IPP-IIG]     Mapping between LPD and IPP Protocols [RFC2569]   Anyone reading these documents for the first time is strongly   encouraged to read the IPP documents in the above order.   This document is laid out as follows:   - The rest ofSection 1 is an introduction to the IPP simplified     model for distributed printing.   -Section 2 introduces the object types covered in the model with     their basic behaviors, attributes, and interactions.   -Section 3 defines the operations included in IPP/1.1.  IPP     operations are synchronous, therefore, for each operation, there is     a both request and a response.   -Section 4 defines the attributes (and their syntaxes) that are used     in the model.   - Sections5 -6 summarizes the implementation conformance     requirements for objects that support the protocol and IANA     considerations, respectively.   - Sections7 -11 cover the Internationalization and Security     considerations as well as References, Author contact information,     and Formats for Registration Proposals.   - Sections12 -14 are appendices that cover Terminology, Status     Codes and Messages, and "media" keyword values.       Note: This document uses terms such as "attributes", "keywords",       and "support".  These terms have special meaning and are defined       in the model terminologysection 12.2.  Capitalized terms, such       as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT, MAY, NEED NOT,       and OPTIONAL, have special meaning relating to conformance.       These terms are defined insection 12.1 on conformance       terminology, most of which is taken fromRFC 2119 [RFC2119].Hastings, et al.            Standards Track                     [Page 9]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   -Section 15 is an appendix that helps to clarify the effects of     interactions between related attributes and their values.   -Section 16 is an appendix that enumerates the subset of Printer     attributes that form a generic directory schema.  These attributes     are useful when registering a Printer so that a client can find the     Printer not just by name, but by filtered searches as well.   -Section 17 is an appendix summarizing the additions and changes     from the IPP/1.0 "Model and Semantics" document [RFC2566] to make     this IPP/1.1 document.   -Section 18 is the full copyright notice.1.1 Simplified Printing Model   In order to achieve its goal of realizing a workable printing   protocol for the Internet, the Internet Printing Protocol (IPP) is   based on a simplified printing model that abstracts the many   components of real world printing solutions.  The Internet is a   distributed computing environment where requesters of print services   (clients, applications, printer drivers, etc.) cooperate and interact   with print service providers.  This model and semantics document   describes a simple, abstract model for IPP even though the underlying   configurations may be complex "n-tier" client/server systems.  An   important simplifying step in the IPP model is to expose only the key   objects and interfaces required for printing.  The model described in   this model document does not include features, interfaces, and   relationships that are beyond the scope of the first version of IPP   (IPP/1.1).  IPP/1.1 incorporates many of the relevant ideas and   lessons learned from other specification and development efforts   [HTPP] [ISO10175] [LDPA] [P1387.4] [PSIS] [RFC1179] [SWP].  IPP is   heavily influenced by the printing model introduced in the Document   Printing Application (DPA) [ISO10175] standard.  Although DPA   specifies both end user and administrative features, IPP version 1.1   (IPP/1.1) focuses primarily on end user functionality with a few   additional OPTIONAL operator operations.   The IPP/1.1 model encapsulates the important components of   distributed printing into two object types:      - Printer (Section 2.1)      - Job (Section 2.2)   Each object type has an associated set of operations (seesection 3)   and attributes (seesection 4).Hastings, et al.            Standards Track                    [Page 10]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   It is important, however, to understand that in real system   implementations (which lie underneath the abstracted IPP/1.1 model),   there are other components of a print service which are not   explicitly defined in the IPP/1.1 model. The following figure   illustrates where IPP/1.1 fits with respect to these other   components.                                +--------------+                                |  Application |                      o         +. . . . . . . |                     \|/        |   Spooler    |                     / \        +. . . . . . . |   +---------+                   End-User     | Print Driver |---|  File   |         +-----------+ +-----+  +------+-------+   +----+----+         |  Browser  | | GUI |         |                |         +-----+-----+ +--+--+         |                |               |          |            |                |               |      +---+------------+---+            |   N   D   S   |      |      IPP Client    |------------+   O   I   E   |      +---------+----------+   T   R   C   |                |   I   E   U   |   F   C   R   -------------- Transport ------------------   I   T   I   C   O   T                    |         --+   A   R   Y           +--------+--------+  |   T   Y               |    IPP Server   |  |   I                   +--------+--------+  |   O                            |           |   N                   +-----------------+  | IPP Printer                       |  Print Service  |  |                       +-----------------+  |                                |         --+                       +-----------------+                       | Output Device(s)|                       +-----------------+   An IPP Printer object encapsulates the functions normally associated   with physical output devices along with the spooling, scheduling and   multiple device management functions often associated with a print   server. Printer objects are optionally registered as entries in a   directory where end users find and select them based on some sort of   filtered and context based searching mechanism (seesection 16).  The   directory is used to store relatively static information about the   Printer, allowing end users to search for and find Printers that   match their search criteria, for example: name, context, printer   capabilities, etc.  The more dynamic information, such as state,   currently loaded and ready media, number of jobs at the Printer,Hastings, et al.            Standards Track                    [Page 11]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   errors, warnings, and so forth, is directly associated with the   Printer object itself rather than with the entry in the directory   which only represents the Printer object.   IPP clients implement the IPP protocol on the client side and give   end users (or programs running on behalf of end users) the ability to   query Printer objects and submit and manage print jobs.  An IPP   server is just that part of the Printer object that implements the   server-side protocol.  The rest of the Printer object implements (or   gateways into) the application semantics of the print service itself.   The Printer objects may be embedded in an output device or may be   implemented on a host on the network that communicates with an output   device.   When a job is submitted to the Printer object and the Printer object   validates the attributes in the submission request, the Printer   object creates a new Job object.  The end user then interacts with   this new Job object to query its status and monitor the progress of   the job.  An end user can also cancel their print jobs by using the   Job object's Cancel-Job operation.  An end-user can also hold,   release, and restart their print jobs using the Job object's OPTIONAL   Hold-Job, Release-Job, and Restart-Job operations, if implemented.   A privileged operator or administrator of a Printer object can   cancel, hold, release, and restart any user's job using the REQUIRED   Cancel-Job and the OPTIONAL Hold-Job, Release-Job, and Restart-Job   operations.  In additional privileged operator or administrator of a   Printer object can pause, resume, or purge (jobs from) a Printer   object using the OPTIONAL Pause-Printer, Resume-Printer, and Purge-   Jobs operations, if implemented.   The notification service is out of scope for this IPP/1.1 document,   but using such a notification service, the end user is able to   register for and receive Printer specific and Job specific events.   An end user can query the status of Printer objects and can follow   the progress of Job objects by polling using the Get-Printer-   Attributes, Get-Jobs, and Get-Job-Attributes operations.2. IPP Objects   The IPP/1.1 model introduces objects of type Printer and Job.  Each   type of object models relevant aspects of a real-world entity such as   a real printer or real print job.  Each object type is defined as a   set of possible attributes that may be supported by instances of that   object type.  For each object (instance), the actual set of supported   attributes and values describe a specific implementation.  The   object's attributes and values describe its state, capabilities,   realizable features, job processing functions, and default behaviorsHastings, et al.            Standards Track                    [Page 12]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   and characteristics.  For example, the Printer object type is defined   as a set of attributes that each Printer object potentially supports.   In the same manner, the Job object type is defined as a set of   attributes that are potentially supported by each Job object.   Each attribute included in the set of attributes defining an object   type is labeled as:   - "REQUIRED": each object MUST support the attribute.   - "RECOMMENDED": each object SHOULD support the attribute.   - "OPTIONAL": each object MAY support the attribute.   Some definitions of attribute values indicate that an object MUST or   SHOULD support the value; otherwise, support of the value is   OPTIONAL.   However, if an implementation supports an attribute, it MUST support   at least one of the possible values for that attribute.2.1 Printer Object   The major component of the IPP/1.1 model is the Printer object.  A   Printer object implements the server-side of the IPP/1.1 protocol.   Using the protocol, end users may query the attributes of the Printer   object and submit print jobs to the Printer object.  The actual   implementation components behind the Printer abstraction may take on   different forms and different configurations.  However, the model   abstraction allows the details of the configuration of real   components to remain opaque to the end user.Section 3 describes   each of the Printer operations in detail.   The capabilities and state of a Printer object are described by its   attributes.  Printer attributes are divided into two groups:   - "job-template" attributes: These attributes describe supported job     processing capabilities and defaults for the Printer object. (Seesection 4.2)   - "printer-description" attributes: These attributes describe the     Printer object's identification, state, location, references to     other sources of information about the Printer object, etc. (seesection 4.4)   Since a Printer object is an abstraction of a generic document output   device and print service provider, a Printer object could be used to   represent any real or virtual device with semantics consistent with   the Printer object, such as a fax device, an imager, or even a CD   writer.Hastings, et al.            Standards Track                    [Page 13]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Some examples of configurations supporting a Printer object include:      1) An output device with no spooling capabilities      2) An output device with a built-in spooler      3) A print server supporting IPP with one or more associated         output devices         3a) The associated output devices may or may not be capable of             spooling jobs         3b) The associated output devices may or may not support IPP   The following figures show some examples of how Printer objects can   be realized on top of various distributed printing configurations.   The embedded case below represents configurations 1 and 2. The hosted   and fan-out figures below represent configurations 3a and 3b.   In this document the term "client" refers to a software entity that   sends IPP operation requests to an IPP Printer object and accepts IPP   operation responses.  A client MAY be:      1. contained within software controlled by an end user, e.g.         activated by the "Print" menu item in an application or      2. the print server component that sends IPP requests to either an         output device or another "downstream" print server.   The term "IPP Printer" is a network entity that accepts IPP operation   requests and returns IPP operation responses.  As such, an IPP object   MAY be:      1. an (embedded) device component that accepts IPP requests and         controls the device or      2. a component of a print server that accepts IPP requests (where         the print server controls one or more networked devices using         IPP or other protocols).   Legend:   ##### indicates a Printer object which is         either embedded in an output device or is         hosted in a server.  The Printer object         might or might not be capable of queuing/spooling.   any   indicates any network protocol or direct         connect, including IPPHastings, et al.            Standards Track                    [Page 14]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   embedded printer:                                             output device                                           +---------------+    O   +--------+                         |  ###########  |   /|\  | client |------------IPP------------># Printer #  |   / \  +--------+                         |  # Object  #  |                                           |  ###########  |                                           +---------------+   hosted printer:                                           +---------------+    O   +--------+        ###########      |               |   /|\  | client |--IPP--># Printer #-any->| output device |   / \  +--------+        # Object  #      |               |                          ###########      +---------------+                                            +---------------+   fan out:                                 |               |                                        +-->| output device |                                    any/    |               |    O   +--------+      ###########   /     +---------------+   /|\  | client |-IPP-># Printer #--*   / \  +--------+      # Object  #   \     +---------------+                        ########### any\    |               |                                        +-->| output device |                                            |               |                                            +---------------+2.2 Job Object   A Job object is used to model a print job.  A Job object contains   documents.  The information required to create a Job object is sent   in a create request from the end user via an IPP Client to the   Printer object.  The Printer object validates the create request, and   if the Printer object accepts the request, the Printer object creates   the new Job object.Section 3 describes each of the Job operations   in detail.   The characteristics and state of a Job object are described by its   attributes.  Job attributes are grouped into two groups as follows:      - "job-template" attributes: These attributes can be supplied by        the client or end user and include job processing instructions        which are intended to override any Printer object defaults        and/or instructions embedded within the document data. (Seesection 4.2)Hastings, et al.            Standards Track                    [Page 15]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      - "job-description" attributes: These attributes describe the Job        object's identification, state, size, etc. The client supplies        some of these attributes, and the Printer object generates        others. (Seesection 4.3)   An implementation MUST support at least one document per Job object.   An implementation MAY support multiple documents per Job object.  A   document is either:      - a stream of document data in a format supported by the Printer        object (typically a Page Description Language - PDL), or      - a reference to such a stream of document data   In IPP/1.1, a document is not modeled as an IPP object, therefore it   has no object identifier or associated attributes.  All job   processing instructions are modeled as Job object attributes.  These   attributes are called Job Template attributes and they apply equally   to all documents within a Job object.2.3 Object Relationships   IPP objects have relationships that are maintained persistently along   with the persistent storage of the object attributes.   A Printer object can represent either one or more physical output   devices or a logical device which "processes" jobs but never actually   uses a physical output device to put marks on paper.  Examples of   logical devices include a Web page publisher or a gateway into an   online document archive or repository.  A Printer object contains   zero or more Job objects.   A Job object is contained by exactly one Printer object, however the   identical document data associated with a Job object could be sent to   either the same or a different Printer object.  In this case, a   second Job object would be created which would be almost identical to   the first Job object, however it would have new (different) Job   object identifiers (seesection 2.4).   A Job object is either empty (before any documents have been added)   or contains one or more documents.  If the contained document is a   stream of document data, that stream can be contained in only one   document.  However, there can be identical copies of the stream in   other documents in the same or different Job objects.  If the   contained document is just a reference to a stream of document data,   other documents (in the same or different Job object(s)) may contain   the same reference.Hastings, et al.            Standards Track                    [Page 16]

RFC 2911              IPP/1.1: Model and Semantics        September 20002.4 Object Identity   All Printer and Job objects are identified by a Uniform Resource   Identifier (URI) [RFC2396] so that they can be persistently and   unambiguously referenced.  Since every URL is a specialized form of a   URI, even though the more generic term URI is used throughout the   rest of this document, its usage is intended to cover the more   specific notion of URL as well.   An administrator configures Printer objects to either support or not   support authentication and/or message privacy using Transport Layer   Security (TLS) [RFC2246] (the mechanism for security configuration is   outside the scope of this IPP/1.1 document).  In some situations,   both types of connections (both authenticated and unauthenticated)   can be established using a single communication channel that has some   sort of negotiation mechanism.  In other situations, multiple   communication channels are used, one for each type of security   configuration.Section 8 provides a full description of all security   considerations and configurations.   If a Printer object supports more than one communication channel,   some or all of those channels might support and/or require different   security mechanisms.  In such cases, an administrator could expose   the simultaneous support for these multiple communication channels as   multiple URIs for a single Printer object where each URI represents   one of the communication channels to the Printer object. To support   this flexibility, the IPP Printer object type defines a multi-valued   identification attribute called the "printer-uri-supported"   attribute.  It MUST contain at least one URI.  It MAY contain more   than one URI.  That is, every Printer object will have at least one   URI that identifies at least one communication channel to the Printer   object, but it may have more than one URI where each URI identifies a   different communication channel to the Printer object.  The   "printer-uri-supported" attribute has two companion attributes, the   "uri-security-supported" attribute and the "uri-authentication-   supported". Both have the same cardinality as "printer-uri-   supported".  The purpose of the "uri-security-supported" attribute is   to indicate the security mechanisms (if any) used for each URI listed   in "printer-uri-supported". The purpose of the "uri-authentication-   supported" attribute is to indicate the authentication mechanisms (if   any) used for each URI listed in "printer-uri-supported".  These   three attributes are fully described in sections4.4.1,4.4.2, and   4.4.3.   When a job is submitted to the Printer object via a create request,   the client supplies only a single Printer object URI.  The client   supplied Printer object URI MUST be one of the values in the   "printer-uri-supported" Printer attribute.Hastings, et al.            Standards Track                    [Page 17]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   IPP/1.1 does not specify how the client obtains the client supplied   URI, but it is RECOMMENDED that a Printer object be registered as an   entry in a directory service.  End-users and programs can then   interrogate the directory searching for Printers.Section 16 defines   a generic schema for Printer object entries in the directory service   and describes how the entry acts as a bridge to the actual IPP   Printer object.  The entry in the directory that represents the IPP   Printer object includes the possibly many URIs for that Printer   object as values in one its attributes.   When a client submits a create request to the Printer object, the   Printer object validates the request and creates a new Job object.   The Printer object assigns the new Job object a URI which is stored   in the "job-uri" Job attribute.  This URI is then used by clients as   the target for subsequent Job operations.  The Printer object   generates a Job URI based on its configured security policy and the   URI used by the client in the create request.   For example, consider a Printer object that supports both a   communication channel secured by the use of SSL3 (using HTTP over   SSL3 with an "https" schemed URI) and another open communication   channel that is not secured with SSL3 (using a simple "http" schemed   URI).  If a client were to submit a job using the secure URI, the   Printer object would assign the new Job object a secure URI as well.   If a client were to submit a job using the open-channel URI, the   Printer would assign the new Job object an open-channel URI.   In addition, the Printer object also populates the Job object's   "job-printer-uri" attribute.  This is a reference back to the Printer   object that created the Job object.  If a client only has access to a   Job object's "job-uri" identifier, the client can query the Job's   "job-printer-uri" attribute in order to determine which Printer   object created the Job object.  If the Printer object supports more   than one URI, the Printer object picks the one URI supplied by the   client when creating the job to build the value for and to populate   the Job's "job-printer-uri" attribute.   Allowing Job objects to have URIs allows for flexibility and   scalability.  For example, in some implementations, the Printer   object might create Jobs that are processed in the same local   environment as the Printer object itself.  In this case, the Job URI   might just be a composition of the Printer's URI and some unique   component for the Job object, such as the unique 32-bit positive   integer mentioned later in this paragraph.  In other implementations,   the Printer object might be a central clearing-house for validating   all Job object creation requests, but the Job object itself might be   created in some environment that is remote from the Printer object.   In this case, the Job object's URI may have no physical-locationHastings, et al.            Standards Track                    [Page 18]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   relationship at all to the Printer object's URI.  Again, the fact   that Job objects have URIs allows for flexibility and scalability,   however, many existing printing systems have local models or   interface constraints that force print jobs to be identified using   only a 32-bit positive integer rather than an independent URI.  This   numeric Job ID is only unique within the context of the Printer   object to which the create request was originally submitted.   Therefore, in order to allow both types of client access to IPP Job   objects (either by Job URI or by numeric Job ID), when the Printer   object successfully processes a create request and creates a new Job   object, the Printer object MUST generate both a Job URI and a Job ID.   The Job ID (stored in the "job-id" attribute) only has meaning in the   context of the Printer object to which the create request was   originally submitted. This requirement to support both Job URIs and   Job IDs allows all types of clients to access Printer objects and Job   objects no matter the local constraints imposed on the client   implementation.   In addition to identifiers, Printer objects and Job objects have   names ("printer-name" and "job-name").  An object name NEED NOT be   unique across all instances of all objects. A Printer object's name   is chosen and set by an administrator through some mechanism outside   the scope of this IPP/1.1 document.  A Job object's name is   optionally chosen and supplied by the IPP client submitting the job.   If the client does not supply a Job object name, the Printer object   generates a name for the new Job object.  In all cases, the name only   has local meaning.   To summarize:      - Each Printer object is identified with one or more URIs.  The        Printer's "printer-uri-supported" attribute contains the URI(s).      - The Printer object's "uri-security-supported" attribute        identifies the communication channel security protocols that may        or may not have been configured for the various Printer object        URIs (e.g., 'tls' or 'none').      - The Printer object's "uri-authentication-supported" attribute        identifies the authentication mechanisms that may or may not        have been configured for the various Printer object URIs (e.g.,        'digest' or 'none').      - Each Job object is identified with a Job URI.  The Job's "job-        uri" attribute contains the URI.      - Each Job object is also identified with Job ID which is a 32-        bit, positive integer.  The Job's "job-id" attribute contains        the Job ID.  The Job ID is only unique within the context of the        Printer object  which created the Job object.Hastings, et al.            Standards Track                    [Page 19]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      - Each Job object has a "job-printer-uri" attribute which contains        the URI of the Printer object that was used to create the Job        object.  This attribute is used to determine the Printer object        that created a Job object when given only the URI for the Job        object.  This linkage is necessary to determine the languages,        charsets, and operations which are supported on that Job (the        basis for such support comes from the creating Printer object).      - Each Printer object has a name (which is not necessarily        unique).  The administrator chooses and sets this name through        some mechanism outside the scope of this IPP/1.1 document.  The        Printer object's "printer-name" attribute contains the name.      - Each Job object has a name (which is not necessarily unique).        The client optionally supplies this name in the create request.        If the client does not supply this name, the Printer object        generates a name for the Job object. The Job object's "job-name"        attribute contains the name.3. IPP Operations   IPP objects support operations.  An operation consists of a request   and a response.  When a client communicates with an IPP object, the   client issues an operation request to the URI for that object.   Operation requests and responses have parameters that identify the   operation.  Operations also have attributes that affect the run-time   characteristics of the operation (the intended target, localization   information, etc.).  These operation-specific attributes are called   operation attributes (as compared to object attributes such as   Printer object attributes or Job object attributes).  Each request   carries along with it any operation attributes, object attributes,   and/or document data required to perform the operation.  Each request   requires a response from the object.  Each response indicates success   or failure of the operation with a status code as a response   parameter.  The response contains any operation attributes, object   attributes, and/or status messages generated during the execution of   the operation request.   This section describes the semantics of the IPP operations, both   requests and responses, in terms of the parameters, attributes, and   other data associated with each operation.Hastings, et al.            Standards Track                    [Page 20]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The IPP/1.1 Printer operations are:     Print-Job (section 3.2.1)     Print-URI (section 3.2.2)     Validate-Job (section 3.2.3)     Create-Job (section 3.2.4)     Get-Printer-Attributes (section 3.2.5)     Get-Jobs (section 3.2.6)     Pause-Printer (section 3.3.5)     Resume-Printer (section 3.3.6)     Purge-Jobs (section 3.3.7)   The Job operations are:     Send-Document (section 3.3.1)     Send-URI (section 3.3.2)     Cancel-Job (section 3.3.3)     Get-Job-Attributes (section 3.3.4)     Hold-Job (section 3.3.5)     Release-Job (section 3.3.6)     Restart-Job (section 3.3.7)   The Send-Document and Send-URI Job operations are used to add a new   document to an existing multi-document Job object created using the   Create-Job operation.3.1 Common Semantics   All IPP operations require some common parameters and operation   attributes.  These common elements and their semantic characteristics   are defined and described in more detail in the following sections.3.1.1 Required Parameters   Every operation request contains the following REQUIRED parameters:      - a "version-number",      - an "operation-id",      - a "request-id", and      - the attributes that are REQUIRED for that type of request.   Every operation response contains the following REQUIRED parameters:      - a "version-number",      - a "status-code",      - the "request-id" that was supplied in the corresponding request,        and      - the attributes that are REQUIRED for that type of response.Hastings, et al.            Standards Track                    [Page 21]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The "Encoding and Transport" document [RFC2910] defines special rules   for the encoding of these parameters.  All other operation elements   are represented using the more generic encoding rules for attributes   and groups of attributes.3.1.2 Operation IDs and Request IDs   Each IPP operation request includes an identifying "operation-id"   value.  Valid values are defined in the "operations-supported"   Printer attribute section (seesection 4.4.15).  The client specifies   which operation is being requested by supplying the correct   "operation-id" value.   In addition, every invocation of an operation is identified by a   "request-id" value. For each request, the client chooses the   "request-id" which MUST be an integer (possibly unique depending on   client requirements) in the range from 1 to 2**31 - 1 (inclusive).   This "request-id" allows clients to manage multiple outstanding   requests. The receiving IPP object copies all 32-bits of the client-   supplied "request-id" attribute into the response so that the client   can match the response with the correct outstanding request, even if   the "request-id" is out of range.  If the request is terminated   before the complete "request-id" is received, the IPP object rejects   the request and returns a response with a "request-id" of 0.   Note: In some cases, the transport protocol underneath IPP might be a   connection oriented protocol that would make it impossible for a   client to receive responses in any order other than the order in   which the corresponding requests were sent.  In such cases, the   "request-id" attribute would not be essential for correct protocol   operation.  However, in other mappings, the operation responses can   come back in any order.  In these cases, the "request-id" would be   essential.3.1.3 Attributes   Operation requests and responses are both composed of groups of   attributes and/or document data.  The attributes groups are:      - Operation Attributes: These attributes are passed in the        operation and affect the IPP object's behavior while processing        the operation request and may affect other attributes or groups        of attributes.  Some operation attributes describe the document        data associated with the print job and are associated with new        Job objects, however most operation attributes do not persist        beyond the life of the operation.  The description of each        operation attribute includes conformance statements indicating        which operation attributes are REQUIRED and which are OPTIONALHastings, et al.            Standards Track                    [Page 22]

RFC 2911              IPP/1.1: Model and Semantics        September 2000        for an IPP object to support and which attributes a client MUST        supply in a request and an IPP object MUST supply in a response.      - Job Template Attributes: These attributes affect the processing        of a job.  A client OPTIONALLY supplies Job Template Attributes        in a create request, and the receiving object MUST be prepared        to receive all supported attributes.  The Job object can later        be queried to find out what Job Template attributes were        originally requested in the create request, and such attributes        are returned in the response as Job Object Attributes.  The        Printer object can be queried about its Job Template attributes        to find out what type of job processing capabilities are        supported and/or what the default job processing behaviors are,        though such attributes are returned in the response as Printer        Object Attributes.  The "ipp-attribute-fidelity" operation        attribute affects processing of all client-supplied Job Template        attributes (see sections3.2.1.2 and15 for a full description        of "ipp-attribute-fidelity" and its relationship to other        attributes).      - Job Object Attributes: These attributes are returned in response        to a query operation directed at a Job object.      - Printer Object Attributes: These attributes are returned in        response to a query operation directed at a Printer object.      - Unsupported Attributes: In a create request, the client supplies        a set of Operation and Job Template attributes.  If any of these        attributes or their values is unsupported by the Printer object,        the Printer object returns the set of unsupported attributes in        the response.  Sections3.1.7,3.2.1.2, and  15 give a full        description of how Job Template attributes supplied by the        client in a create request are processed by the Printer object        and how unsupported attributes are returned to the client.        Because of extensibility, any IPP object might receive a request        that contains new or unknown attributes or values for which it        has no support. In such cases, the IPP object processes what it        can and returns the unsupported attributes in the response. The        Unsupported Attribute group is defined for all operation        responses for returning unsupported attributes that the client        supplied in the request.   Later in this section, each operation is formally defined by   identifying the allowed and expected groups of attributes for each   request and response.  The model identifies a specific order for each   group in each request or response, but the attributes within each   group may be in any order, unless specified otherwise.   The attributes within a group MUST be unique; if an attribute with   the same name occurs more than once, the group is mal-formed.   Clients MUST NOT submit such malformed requests and Printers MUST NOT   return such malformed responses.  If such a malformed request isHastings, et al.            Standards Track                    [Page 23]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   submitted to a Printer, the Printer MUST either (1) reject the   request with the 'client-error-bad-request' status code (seesection13.1.4.1) or (2) process the request normally after selecting only   one of the attribute instances, depending on implementation.  Which   attribute is selected when there are duplicate attributes depends on   implementation.  The IPP Printer MUST NOT use the values from more   than one such duplicate attribute instance.   Each attribute definition includes the attribute's name followed by   the name of its attribute syntax(es) in parenthesizes.  In addition,   each 'integer' attribute is followed by the allowed range in   parentheses, (m:n), for values of that attribute.  Each 'text' or   'name' attribute is followed by the maximum size in octets in   parentheses, (size), for values of that attribute. For more details   on attribute syntax notation, see the descriptions of these   attributes syntaxes insection 4.1.   Note: Document data included in the operation is not strictly an   attribute, but it is treated as a special attribute group for   ordering purposes.  The only operations that support supplying the   document data within an operation request are Print-Job and Send-   Document.  There are no operation responses that include document   data.   Some operations are REQUIRED for IPP objects to support; the others   are OPTIONAL (seesection 5.2.2).  Therefore, before using an   OPTIONAL operation, a client SHOULD first use the REQUIRED Get-   Printer-Attributes operation to query the Printer's "operations-   supported" attribute in order to determine which OPTIONAL Printer and   Job operations are actually supported.  The client SHOULD NOT use an   OPTIONAL operation that is not supported.  When an IPP object   receives a request to perform an operation it does not support, it   returns the 'server-error-operation-not-supported' status code (seesection 13.1.5.2).  An IPP object is non-conformant if it does not   support a REQUIRED operation.3.1.4 Character Set and Natural Language Operation Attributes   Some Job and Printer attributes have values that are text strings and   names intended for human understanding rather than machine   understanding (see the 'text' and 'name' attribute syntax   descriptions insection 4.1).  The following sections describe two   special Operation Attributes called "attributes-charset" and   "attributes-natural-language".  These attributes are always part of   the Operation Attributes group.  For most attribute groups, the order   of the attributes within the group is not important.  However, for   these two attributes within the Operation Attributes group, the order   is critical.  The "attributes-charset" attribute MUST be the firstHastings, et al.            Standards Track                    [Page 24]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   attribute in the group and the "attributes-natural-language"   attribute MUST be the second attribute in the group.  In other words,   these attributes MUST be supplied in every IPP request and response,   they MUST come first in the group, and MUST come in the specified   order.  For job creation operations, the IPP Printer implementation   saves these two attributes with the new Job object as Job Description   attributes.  For the sake of brevity in this document, these   operation attribute descriptions are not repeated with every   operation request and response, but have a reference back to this   section instead.3.1.4.1 Request Operation Attributes   The client MUST supply and the Printer object MUST support the   following REQUIRED operation attributes in every IPP/1.1 operation   request:      "attributes-charset" (charset):         This operation attribute identifies the charset (coded         character set and encoding method) used by any 'text' and         'name' attributes that the client is supplying in this request.         It also identifies the charset that the Printer object MUST use         (if supported) for all 'text' and 'name' attributes and status         messages that the Printer object returns in the response to         this request. See Sections4.1.1 and4.1.2 for the definition         of the 'text' and 'name' attribute syntaxes.         All clients and IPP objects MUST support the 'utf-8' charset         [RFC2279] and MAY support additional charsets provided that         they are registered with IANA [IANA-CS].  If the Printer object         does not support the client supplied charset value, the Printer         object MUST reject the request, set the "attributes-charset" to         'utf-8' in the response, and return the 'client-error-charset-         not-supported' status code and any 'text' or 'name' attributes         using the 'utf-8' charset. The Printer NEED NOT return any         attributes in the Unsupported Attributes Group (See sections         3.1.7 and 3.2.1.2).  The Printer object MUST indicate the         charset(s) supported as the values of the "charset-supported"         Printer attribute (seeSection 4.4.18), so that the client can         query to determine which charset(s) are supported.         Note to client implementers: Since IPP objects are only         required to support the 'utf-8' charset, in order to maximize         interoperability with multiple IPP object implementations, a         client may want to supply 'utf-8' in the "attributes-charset"         operation attribute, even though the client is only passing and         able to present a simpler charset, such as US-ASCII [ASCII] or         ISO-8859-1 [ISO8859-1].  Then the client will have to filterHastings, et al.            Standards Track                    [Page 25]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         out (or charset convert) those characters that are returned in         the response that it cannot present to its user.  On the other         hand, if both the client and the IPP objects also support a         charset in common besides utf-8, the client may want to use         that charset in order to avoid charset conversion or data loss.         See the 'charset' attribute syntax description inSection 4.1.7         for the syntax and semantic interpretation of the values of         this attribute and for example values.      "attributes-natural-language" (naturalLanguage):         This operation attribute identifies the natural language used         by any 'text' and 'name' attributes that the client is         supplying in this request.  This attribute also identifies the         natural language that the Printer object SHOULD use for all         'text' and 'name' attributes and status messages that the         Printer object returns in the response to this request.  See         the 'naturalLanguage' attribute syntax description insection4.1.8 for the syntax and semantic interpretation of the values         of this attribute and for example values.         There are no REQUIRED natural languages required for the         Printer object to support.  However, the Printer object's         "generated-natural-language-supported" attribute identifies the         natural languages supported by the Printer object and any         contained Job objects for all text strings generated by the IPP         object.  A client MAY query this attribute to determine which         natural language(s) are supported for generated messages.         For any of the attributes for which the Printer object         generates text, i.e., for the "job-state-message", "printer-         state-message", and status messages (seeSection 3.1.6), the         Printer object MUST be able to generate these text strings in         any of its supported natural languages.  If the client requests         a natural language that is not supported, the Printer object         MUST return these generated messages in the Printer's         configured natural language as specified by the Printer's         "natural-language-configured" attribute" (seeSection 4.4.19).         For other 'text' and 'name' attributes supplied by the client,         authentication system, operator, system administrator, or         manufacturer (i.e., for "job-originating-user-name", "printer-         name" (name), "printer-location" (text), "printer-info" (text),         and "printer-make-and-model" (text)), the Printer object is         only required to support the configured natural language of theHastings, et al.            Standards Track                    [Page 26]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         Printer identified by the Printer object's "natural-language-         configured" attribute, though support of additional natural         languages for these attributes is permitted.         For any 'text' or 'name' attribute in the request that is in a         different natural language than the value supplied in the         "attributes-natural-language" operation attribute, the client         MUST use the Natural Language Override mechanism (see sections         4.1.1.2 and 4.1.2.2) for each such attribute value supplied.         The client MAY use the Natural Language Override mechanism         redundantly, i.e., use it even when the value is in the same         natural language as the value supplied in the "attributes-         natural-language" operation attribute of the request.         The IPP object MUST accept any natural language and any Natural         Language Override, whether the IPP object supports that natural         language or not (and independent of the value of the "ipp-         attribute-fidelity" Operation attribute).  That is the IPP         object accepts all client supplied values no matter what the         values are in the Printer object's "generated-natural-         language-supported" attribute.  That attribute, "generated-         natural-language-supported", only applies to generated         messages, not client supplied messages.  The IPP object MUST         remember that natural language for all client-supplied         attributes, and when returning those attributes in response to         a query, the IPP object MUST indicate that natural language.         Each value whose attribute syntax type is 'text' or 'name' (see         sections4.1.1 and4.1.2) has an Associated Natural-Language.         This document does not specify how this association is stored         in a Printer or Job object.  When such a value is encoded in a         request or response, the natural language is either implicit or         explicit:         - In the implicit case, the value contains only the text/name           value, and the language is specified by the "attributes-           natural-language" operation attribute in the request or           response (see sections4.1.1.1 textWithoutLanguage and           4.1.2.1 nameWithoutLanguage).         - In the explicit case (also known as the Natural-Language           Override case), the value contains both the language and the           text/name value (see sections4.1.1.2 textWithLanguage and           4.1.2.2 nameWithLanguage).         For example, the "job-name" attribute MAY be supplied by the         client in a create request.  The text value for this attribute         will be in the natural language identified by the "attribute-Hastings, et al.            Standards Track                    [Page 27]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         natural-language" attribute, or if different, as identified by         the Natural Language Override mechanism.  If supplied, the IPP         object will use the value of the "job-name" attribute to         populate the Job object's "job-name" attribute.  Whenever any         client queries the Job object's "job-name" attribute, the IPP         object returns the attribute as stored and uses the Natural         Language Override mechanism to specify the natural language, if         it is different from that reported in the "attributes-natural-         language" operation attribute of the response.  The IPP object         MAY use the Natural Language Override mechanism redundantly,         i.e., use it even when the value is in the same natural         language as the value supplied in the "attributes-natural-         language" operation attribute of the response.         An IPP object MUST NOT reject a request based on a supplied         natural language in an "attributes-natural-language" Operation         attribute or in any attribute that uses the Natural Language         Override.   Clients SHOULD NOT supply 'text' or 'name' attributes that use an   illegal combination of natural language and charset.  For example,   suppose a Printer object supports charsets 'utf-8', 'iso-8859-1', and   'iso-8859-7'.  Suppose also, that it supports natural languages 'en'   (English), 'fr' (French), and 'el' (Greek).  Although the Printer   object supports the charset 'iso-8859-1' and natural language 'el',   it probably does not support the combination of Greek text strings   using the 'iso-8859-1' charset.  The Printer object handles this   apparent incompatibility differently depending on the context in   which it occurs:      - In a create request: If the client supplies a text or name        attribute (for example, the "job-name" operation attribute) that        uses an apparently incompatible combination, it is a client        choice that does not affect the Printer object or its correct        operation.  Therefore, the Printer object simply accepts the        client supplied value, stores it with the Job object, and        responds back with the same combination whenever the client (or        any client) queries for that attribute.      - In a query-type operation, like Get-Printer-Attributes: If the        client requests an apparently incompatible combination, the        Printer object responds (as described insection 3.1.4.2) using        the Printer's configured natural language rather than the        natural language requested by the client.   In either case, the Printer object does not reject the request   because of the apparent incompatibility.  The potential incompatible   combination of charset and natural language can occur either at the   global operation level or at the Natural Language OverrideHastings, et al.            Standards Track                    [Page 28]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   attribute-by-attribute level.  In addition, since the response always   includes explicit charset and natural language information, there is   never any question or ambiguity in how the client interprets the   response.3.1.4.2 Response Operation Attributes   The Printer object MUST supply and the client MUST support the   following REQUIRED operation attributes in every IPP/1.1 operation   response:      "attributes-charset" (charset):         This operation attribute identifies the charset used by any         'text' and 'name' attributes that the Printer object is         returning in this response.  The value in this response MUST be         the same value as the "attributes-charset" operation attribute         supplied by the client in the request.  If this is not possible         (i.e., the charset requested is not supported), the request         would have been rejected.  See "attributes-charset" described         inSection 3.1.4.1 above.         If the Printer object supports more than just the 'utf-8'         charset, the Printer object MUST be able to code convert         between each of the charsets supported on a highest fidelity         possible basis in order to return the 'text' and 'name'         attributes in the charset requested by the client.  However,         some information loss MAY occur during the charset conversion         depending on the charsets involved.  For example, the Printer         object may convert from a UTF-8 'a' to a US-ASCII 'a' (with no         loss of information), from an ISO Latin 1 CAPITAL LETTER A WITH         ACUTE ACCENT to US-ASCII 'A' (losing the accent), or from a         UTF-8 Japanese Kanji character to some ISO Latin 1 error         character indication such as '?', decimal code equivalent, or         to the absence of a character, depending on implementation.         Whether an implementation that supports more than one charset         stores the data in the charset supplied by the client or code         converts to one of the other supported charsets, depends on         implementation.  The strategy should try to minimize loss of         information during code conversion.  On each response, such an         implementation converts from its internal charset to that         requested.      "attributes-natural-language" (naturalLanguage):         This operation attribute identifies the natural language used         by any 'text' and 'name' attributes that the IPP object is         returning in this response.  Unlike the "attributes-charset"         operation attribute, the IPP object NEED NOT return the sameHastings, et al.            Standards Track                    [Page 29]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         value as that supplied by the client in the request.  The IPP         object MAY return the natural language of the Job object or the         Printer's configured natural language as identified by the         Printer object's "natural-language-configured" attribute,         rather than the natural language supplied by the client.  For         any 'text' or 'name' attribute or status message in the         response that is in a different natural language than the value         returned in the "attributes-natural-language" operation         attribute, the IPP object MUST use the Natural Language         Override mechanism (see sections4.1.1.2 and4.1.2.2) on each         attribute value returned.  The IPP object MAY use the Natural         Language Override mechanism redundantly, i.e., use it even when         the value is in the same natural language as the value supplied         in the "attributes-natural-language" operation attribute of the         response.3.1.5 Operation Targets   All IPP operations are directed at IPP objects.  For Printer   operations, the operation is always directed at a Printer object   using one of its URIs (i.e., one of the values in the Printer   object's "printer-uri-supported" attribute).  Even if the Printer   object supports more than one URI, the client supplies only one URI   as the target of the operation.  The client identifies the target   object by supplying the correct URI in the "printer-uri (uri)"   operation attribute.   For Job operations, the operation is directed at either:      - The Job object itself using the Job object's URI.  In this case,        the client identifies the target object by supplying the correct        URI in the "job-uri (uri)" operation attribute.      - The Printer object that created the Job object using both the        Printer objects URI and the Job object's Job ID.  Since the        Printer object that created the Job object generated the Job ID,        it MUST be able to correctly associate the client supplied Job        ID with the correct Job object.  The client supplies the Printer        object's URI in the "printer-uri (uri)" operation attribute and        the Job object's Job ID in the "job-id (integer(1:MAX))"        operation attribute.   If the operation is directed at the Job object directly using the Job   object's URI, the client MUST NOT include the redundant "job-id"   operation attribute.Hastings, et al.            Standards Track                    [Page 30]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The operation target attributes are REQUIRED operation attributes   that MUST be included in every operation request.  Like the charset   and natural language attributes (seesection 3.1.4), the operation   target attributes are specially ordered operation attributes.  In all   cases, the operation target attributes immediately follow the   "attributes-charset" and "attributes-natural-language" attributes   within the operation attribute group, however the specific ordering   rules are:      - In the case where there is only one operation target attribute        (i.e., either only the "printer-uri" attribute or only the        "job-uri" attribute), that attribute MUST be the third attribute        in the operation attributes group.      - In the case where Job operations use two operation target        attributes (i.e., the "printer-uri" and "job-id" attributes),        the "printer-uri" attribute MUST be the third attribute and the        "job-id" attribute MUST be the fourth attribute.   In all cases, the target URIs contained within the body of IPP   operation requests and responses must be in absolute format rather   than relative format (a relative URL identifies a resource with the   scope of the HTTP server, but does not include scheme, host or port).   The following rules apply to the use of port numbers in URIs that   identify IPP objects:      1. If the URI scheme allows the port number to be explicitly         included in the URI string, and a port number is specified         within the URI, then that port number MUST be used by the         client to contact the IPP object.      2. If the URI scheme allows the port number to be explicitly         included in the URI string, and a port number is not specified         within the URI, then default port number implied by that URI         scheme MUST be used by the client to contact the IPP object.      3. If the URI scheme does not allow an explicit port number to be         specified within the URI, then the default port number implied         by that URI MUST be used by the client to contact the IPP         object.   Note: The IPP "Encoding and Transport document [RFC2910] shows a   mapping of IPP onto HTTP/1.1 [RFC2616] and defines a new default port   number for using IPP over HTTP/1.1.Hastings, et al.            Standards Track                    [Page 31]

RFC 2911              IPP/1.1: Model and Semantics        September 20003.1.6 Operation Response Status Codes and Status Messages   Every operation response includes a REQUIRED "status-code" parameter   and an OPTIONAL "status-message" operation attribute, and an OPTIONAL   "detailed-status-message" operation attribute.  The Print-URI and   Send-URI response MAY include an OPTIONAL "document-access-error"   operation attribute.3.1.6.1 "status-code" (type2 enum)   The REQUIRED "status-code" parameter provides information on the   processing of a request.   The status code is intended for use by automata.  A client   implementation of IPP SHOULD convert status code values into any   localized message that has semantic meaning to the end user.   The "status-code" value is a numeric value that has semantic meaning.   The "status-code" syntax is similar to a "type2 enum" (seesection4.1 on "Attribute Syntaxes") except that values can range only from   0x0000 to 0x7FFF.Section 13 describes the status codes, assigns the   numeric values, and suggests a corresponding status message for each   status code for use by the client when the user's natural language is   English.   If the Printer performs an operation with no errors and it encounters   no problems, it MUST return the status code 'successful-ok' in the   response.  Seesection 13.   If the client supplies unsupported values for the following   parameters or Operation attributes, the Printer object MUST reject   the operation, NEED NOT return the unsupported attribute value in the   Unsupported Attributes group, and MUST return the indicated status   code:        Parameter/Attribute                 Status code        version-number      server-error-version-not-supported        operation-id        server-error-operation-not-supported        attributes-charset  client-error-charset-not-supported        compression         client-error-compression-not-supported        document-format     client-error-document-format-not-supported        document-uri        client-error-uri-scheme-not-supported,                             client-error-document-access-error   If the client supplies unsupported values for other attributes, or   unsupported attributes, the Printer returns the status code defined   insection 3.1.7 on Unsupported Attributes.Hastings, et al.            Standards Track                    [Page 32]

RFC 2911              IPP/1.1: Model and Semantics        September 20003.1.6.2 "status-message" (text(255))   The OPTIONAL "status-message" operation attribute provides a short   textual description of the status of the operation.  The "status-   message" attribute's syntax is "text(255)", so the maximum length is   255 octets (seesection 4.1.1).  The status message is intended for   the human end user.  If a response does include a "status-message"   attribute, an IPP client NEED NOT examine or display the messages,   however it SHOULD do so in some implementation specific manner.  The   "status-message" is especially useful for a later version of a   Printer object to return as supplemental information for the human   user to accompany a status code that an earlier version of a client   might not understand.   If the Printer object supports the "status-message" operation   attribute, the Printer object MUST be able to generate this message   in any of the natural languages identified by the Printer object's   "generated-natural-language-supported" attribute (see the   "attributes-natural-language" operation attribute specified insection 3.1.4.1.Section 13 suggests the text for the status message   returned by the Printer for use with the English natural language.   As described insection 3.1.4.1 for any returned 'text' attribute, if   there is a choice for generating this message, the Printer object   uses the natural language indicated by the value of the "attributes-   natural-language" in the client request if supported, otherwise the   Printer object uses the value in the Printer object's own "natural-   language-configured" attribute.   If the Printer object supports the "status-message" operation   attribute, it SHOULD use the REQUIRED 'utf-8' charset to return a   status message for the following error status codes (seesection 13):   'client-error-bad-request', 'client-error-charset-not-supported',   'server-error-internal-error', 'server-error-operation-not-   supported', and 'server-error-version-not-supported'.  In this case,   it MUST set the value of the "attributes-charset" operation attribute   to 'utf-8' in the error response.3.1.6.3 "detailed-status-message" (text(MAX))   The OPTIONAL "detailed-status-message" operation attribute provides   additional more detailed technical and implementation-specific   information about the operation.  The "detailed-status-message"   attribute's syntax is "text(MAX)", so the maximum length is 1023   octets (seesection 4.1.1).    If the Printer objects supports the   "detailed-status-message" operation attribute, the Printer NEED NOT   localize the message, since it is intended for use by the system   administrator or other experienced technical persons.  LocalizationHastings, et al.            Standards Track                    [Page 33]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   might obscure the technical meaning of such messages.  Clients MUST   NOT attempt to parse the value of this attribute.  See the   "document-access-error" operation attribute (section 3.1.6.4) for   additional errors that a program can process.3.1.6.4 "document-access-error" (text(MAX))   This OPTIONAL operation attribute provides additional information   about any document access errors encountered by the Printer before it   returned a response to the Print-URI (section 3.2.2) or Send-URI   (section 3.3.1) operation.  For errors in the protocol identified by   the URI scheme in the "document-uri" operation attribute, such as   'http:' or 'ftp:', the error code is returned in parentheses,   followed by the URI.  For example:      (404)http://ftp.pwg.org/pub/pwg/ipp/new_MOD/ipp-model-v11.pdf   Most Internet protocols use decimal error codes (unlike IPP), so the   ASCII error code representation is in decimal.3.1.7 Unsupported Attributes   The Unsupported Attributes group contains attributes that are not   supported by the operation. This group is primarily for the job   creation operations, but all operations can return this group.   A Printer object MUST include an Unsupported Attributes group in a   response if the status code is one of the following:  'successful-   ok-ignored-or-substituted-attributes', 'successful-ok-conflicting-   attributes', 'client-error-attributes-or-values-not-supported' or   'client-error-conflicting-attributes'.   If the status code is one of the four specified in the preceding   paragraph, the Unsupported Attributes group MUST contain all of those   attributes and only those attributes that are:      a. an Operation or Job Template attribute supplied in the request,         and      b. unsupported by the printer. See below for details on the three         categories "unsupported" attributes.   If the status code is one of those in the table insection 3.1.6.1,   the Unsupported Attributes group NEED NOT contain the unsupported   parameter or attribute indicated in that table.Hastings, et al.            Standards Track                    [Page 34]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   If the Printer object is not returning any Unsupported Attributes in   the response, the Printer object SHOULD omit Group 2 rather than   sending an empty group.  However, a client MUST be able to accept an   empty group.   Unsupported attributes fall into three categories:      1. The Printer object does not support the supplied attribute (no         matter what the attribute syntax or value).      2. The Printer object does support the attribute, but does not         support some or all of the particular attribute syntaxes or         values supplied by the client (i.e., the Printer object does         not have those attribute syntaxes or values in its         corresponding "xxx-supported" attribute).      3. The Printer object does support the attributes and values         supplied, but the particular values are in conflict with one         another, because they violate a constraint, such as not being         able to staple transparencies.   In the case of an unsupported attribute name, the Printer object   returns the client-supplied attribute with a substituted value of   'unsupported'.  This value's syntax type is "out-of-band" and its   encoding is defined by special rules for "out-of-band" values in the   "Encoding and Transport" document [RFC2910].   Its value indicates no   support for the attribute itself (see the beginning ofsection 4.1).   In the case of a supported attribute with one or more unsupported   attribute syntaxes or values, the Printer object simply returns the   client-supplied attribute with the unsupported attribute syntaxes or   values as supplied by the client.  This indicates support for the   attribute, but no support for that particular attribute syntax or   value.  If the client supplies a multi-valued attribute with more   than one value and the Printer object supports the attribute but only   supports a subset of the client-supplied attribute syntaxes or   values, the Printer object   MUST return only those attribute syntaxes or values that are   unsupported.   In the case of two (or more) supported attribute values that are in   conflict with one another (although each is supported independently,   the values conflict when requested together within the same job), the   Printer object MUST return all the values that it ignores or   substitutes to resolve the conflict, but not any of the values thatHastings, et al.            Standards Track                    [Page 35]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   it is still using.  The choice for exactly how to resolve the   conflict is implementation dependent.  See sections3.2.1.2 and15.   See The Implementer's Guide [IPP-IIG] for an example.3.1.8 Versions   Each operation request and response carries with it a "version-   number" parameter.  Each value of the "version-number" is in the form   "X.Y" where X is the major version number and Y is the minor version   number.  By including a version number in the client request, it   allows the client  to identify which version of IPP it is interested   in using, i.e., the version whose conformance requirements the client   may be depending upon the Printer to meet.   If the IPP object does not support that major version number supplied   by the client, i.e., the major version field of the "version-number"   parameter does not match any of the values of the Printer's "ipp-   versions-supported" (seesection 4.4.14), the object MUST respond   with a status code of 'server-error-version-not-supported' along with   the closest version number that is supported (seesection 13.1.5.4).   If the major version number is supported, but the minor version   number is not, the IPP object SHOULD accept and attempt to perform   the request (or reject the request if the operation is not   supported), else it rejects the request and returns the 'server-   error-version-not-supported' status code.  In all cases, the IPP   object MUST return the "version-number" that it supports that is   closest to the version number supplied by the client in the request.   There is no version negotiation per se.  However, if after receiving   a 'server-error-version-not-supported' status code from an IPP   object, a client SHOULD try again with a different version number. A   client MAY also determine the versions supported either from a   directory that conforms toAppendix E (seesection 16) or by querying   the Printer object's "ipp-versions-supported" attribute (seesection4.4.14) to determine which versions are supported.   An IPP object implementation MUST support version '1.1', i.e., meet   the conformance requirements for IPP/1.1 as specified in this   document and [RFC2910].  It is recommended that IPP object   implementations accept any request with the major version '1' (or   reject the request if the operation is not supported).   There is only one notion of "version number" that covers both IPP   Model and IPP Protocol changes. Thus the version number MUST change   when introducing a new version of the Model and Semantics document   (this document) or a new version of the "Encoding and Transport"   document [RFC2910].Hastings, et al.            Standards Track                    [Page 36]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Changes to the major version number of the Model and Semantics   document indicate structural or syntactic changes that make it   impossible for older version of IPP clients and Printer objects to   correctly parse and correctly process the new or changed attributes,   operations and responses.  If the major version number changes, the   minor version numbers is set to zero.  As an example, adding the   REQUIRED "ipp-attribute-fidelity" attribute to version '1.1' (if it   had not been part of version '1.0'), would have required a change to   the major version number, since an IPP/1.0 Printer would not have   processed a request with the correct semantics that contained the   "ipp-attribute-fidelity" attribute that it did not know about.  Items   that might affect the changing of the major version number include   any changes to the Model and Semantics document (this document) or   the "Encoding and Transport" document [RFC2910] itself, such as:      - reordering of ordered attributes or attribute sets      - changes to the syntax of existing attributes      - adding REQUIRED (for an IPP object to support) operation        attribute groups      - adding values to existing REQUIRED operation attributes      - adding REQUIRED operations   Changes to the minor version number indicate the addition of new   features, attributes and attribute values that may not be understood   by all IPP objects, but which can be ignored if not understood.   Items that might affect the changing of the minor version number   include any changes to the model objects and attributes but not the   encoding and transport rules [RFC2910] (except adding attribute   syntaxes).  Examples of such changes are:      - grouping all extensions not included in a previous version into        a new version      - adding new attribute values      - adding new object attributes      - adding OPTIONAL (for an IPP object to support) operation        attributes (i.e., those attributes that an IPP object can ignore        without confusing clients)      - adding OPTIONAL (for an IPP object to support) operation        attribute groups (i.e., those attributes that an IPP object can        ignore without confusing clients)      - adding new attribute syntaxes      - adding OPTIONAL operations      - changing Job Description attributes or Printer Description        attributes from OPTIONAL to REQUIRED or vice versa.      - adding OPTIONAL attribute syntaxes to an existing attribute.   The encoding of the "version-number" MUST NOT change over any version   number (either major or minor).  This rule guarantees that all futureHastings, et al.            Standards Track                    [Page 37]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   versions will be backwards compatible with all previous versions (at   least for checking  the "version-number").  In addition, any protocol   elements (attributes, error codes, tags, etc.) that are not carried   forward from one version to the next are deprecated so that they can   never be reused with new semantics.   Implementations that support a certain  version NEED NOT support ALL   previous versions.  As each new  version is defined (through the   release of a new IPP specification document), that version will   specify which previous  versions MUST and which versions SHOULD be   supported in compliant implementations.3.1.9 Job Creation Operations   In order to "submit a print job" and create a new Job object, a   client issues a create request.  A create request is any one of   following three operation requests:      - The Print-Job Request: A client that wants to submit a print job        with only a single document uses the Print-Job operation.  The        operation allows for the client to "push" the document data to        the Printer object by including the document data in the request        itself.      - The Print-URI Request: A client that wants to submit a print job        with only a single document (where the Printer object "pulls"        the document data instead of the client "pushing" the data to        the Printer object) uses the Print-URI operation.   In this        case, the client includes in the request only a URI reference to        the document data (not the document data itself).      - The Create-Job Request: A client that wants to submit a print        job with multiple documents uses the Create-Job operation.  This        operation is followed by an arbitrary number (one or more) of        Send-Document and/or Send-URI operations (each creating another        document for the newly create Job object).  The Send-Document        operation includes the document data in the request (the client        "pushes" the document data to the printer), and the Send-URI        operation includes only a URI reference to the document data in        the request (the Printer "pulls" the document data from the        referenced location).  The last Send-Document or Send-URI        request for a given Job object includes a "last-document"        operation attribute set to 'true' indicating that this is the        last request.   Throughout this model document, the term "create request" is used to   refer to any of these three operation requests.Hastings, et al.            Standards Track                    [Page 38]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   A Create-Job operation followed by only one Send-Document operation   is semantically equivalent to a Print-Job operation, however, for   performance reasons, the client SHOULD use the Print-Job operation   for all single document jobs.  Also, Print-Job is a REQUIRED   operation (all implementations MUST support it) whereas Create-Job is   an OPTIONAL operation, hence some implementations might not support   it.   Job submission time is the point in time when a client issues a   create request.  The initial state of every Job object is the   'pending', 'pending-held', or 'processing' state (seesection 4.3.7).   When the Printer object begins processing the print job, the Job   object's state moves to 'processing'.  This is known as job   processing time.  There are validation checks that must be done at   job submission time and others that must be performed at job   processing time.   At job submission time and at the time a Validate-Job operation is   received, the Printer MUST do the following:      1. Process the client supplied attributes and either accept or         reject the request      2. Validate the syntax of and support for the scheme of any client         supplied URI   At job submission time the Printer object MUST validate whether or   not the supplied attributes, attribute syntaxes, and values are   supported by matching them with the Printer object's corresponding   "xxx-supported" attributes.  Seesection 3.1.7 for details.  [IPP-   IIG] presents suggested steps for an IPP object to either accept or   reject any request and additional steps for processing create   requests.   At job submission time the Printer object NEED NOT perform the   validation checks reserved for job processing time such as:      1. Validating the document data      2. Validating the actual contents of any client supplied URI         (resolve the reference and follow the link to the document         data)   At job submission time, these additional job processing time   validation checks are essentially useless, since they require   actually parsing and interpreting the document data, are not   guaranteed to be 100% accurate, and MUST be done, yet again, at job   processing time.  Also, in the case of a URI, checking for   availability at job submission time does not guarantee availabilityHastings, et al.            Standards Track                    [Page 39]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   at job processing time.  In addition, at job processing time, the   Printer object might discover any of the following conditions that   were not detectable at job submission time:      - runtime errors in the document data,      - nested document data that is in an unsupported format,      - the URI reference is no longer valid (i.e., the server hosting        the document might be down), or      - any other job processing error   At job submission time, a Printer object, especially a non-spooling   Printer, MAY accept jobs that it does not have enough space for.  In   such a situation, a Printer object MAY stop reading data from a   client for an indefinite period of time.  A client MUST be prepared   for a write operation to block for an indefinite period of time (seesection 5.1 on client conformance).   When a Printer object has too little space for starting a new job, it   MAY reject a new create request. In this case, a Printer object MUST   return a response (in reply to the rejected request) with a status-   code of 'server-error-busy' (seesection 14.1.5.8) and it MAY close   the connection before receiving all bytes of the operation.  A   Printer SHOULD indicate that it is temporarily unable to accept jobs   by setting the 'spool-space-full' value in its "printer-state-   reasons" attribute and removing the value when it can accept another   job (seesection 4.4.12).   When receiving a 'server-error-busy' status-code in an operation   response, a client MUST be prepared for the Printer object to close   the connection before the client has sent all of the data (especially   for the Print-Job operation). A client MUST be prepared to keep   submitting a create request until the IPP Printer object accepts the   create request.   At job processing time, since the Printer object has already   responded with a successful status code in the response to the create   request, if the Printer object detects an error, the Printer object   is unable to inform the end user of the error with an operation   status code.   In this case, the Printer, depending on the error, can   set the job object's "job-state", "job-state-reasons", or "job-   state-message" attributes to the appropriate value(s) so that later   queries can report the correct job status.   Note: Asynchronous notification of events is outside the scope of   this IPP/1.1 document.Hastings, et al.            Standards Track                    [Page 40]

RFC 2911              IPP/1.1: Model and Semantics        September 20003.2 Printer Operations   All Printer operations are directed at Printer objects.  A client   MUST always supply the "printer-uri" operation attribute in order to   identify the correct target of the operation.3.2.1 Print-Job Operation   This REQUIRED operation allows a client to submit a print job with   only one document and supply the document data (rather than just a   reference to the data).  SeeSection 15 for the suggested steps for   processing create operations and their Operation and Job Template   attributes.3.2.1.1 Print-Job Request   The following groups of attributes are supplied as part of the   Print-Job Request:   Group 1: Operation Attributes      Natural Language and Character Set:         The "attributes-charset" and "attributes-natural-language"         attributes as described insection 3.1.4.1.  The Printer object         MUST copy these values to the corresponding Job Description         attributes described in sections4.3.19 and4.3.20.      Target:         The "printer-uri" (uri) operation attribute which is the target         for this operation as described insection 3.1.5.      Requesting User Name:         The "requesting-user-name" (name(MAX)) attribute SHOULD be         supplied by the client as described insection 8.3.      "job-name" (name(MAX)):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute.  It contains the client         supplied Job name.  If this attribute is supplied by the         client, its value is used for the "job-name" attribute of the         newly created Job object.  The client MAY automatically include         any information that will help the end-user distinguish amongst         his/her jobs, such as the name of the application program along         with information from the document, such as the document name,         document subject, or source file name.  If this attribute is         not supplied by the client, the Printer generates a name to use         in the "job-name" attribute of the newly created Job object         (seeSection 4.3.5).Hastings, et al.            Standards Track                    [Page 41]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      "ipp-attribute-fidelity" (boolean):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute.  The value 'true' indicates         that total fidelity to client supplied Job Template attributes         and values is required, else the Printer object MUST reject the         Print-Job request.  The value 'false' indicates that a         reasonable attempt to print the Job object is acceptable and         the Printer object MUST accept the Print-Job request. If not         supplied, the Printer object assumes the value is 'false'.  All         Printer objects MUST support both types of job processing.  Seesection 15 for a full description of "ipp-attribute-fidelity"         and its relationship to other attributes, especially the         Printer object's "pdl-override-supported" attribute.      "document-name" (name(MAX)):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute.   It contains the client         supplied document name.  The document name MAY be different         than the Job name.  Typically, the client software         automatically supplies the document name on behalf of the end         user by using a file name or an application generated name.  If         this attribute is supplied, its value can be used in a manner         defined by each implementation.  Examples include: printed         along with the Job (job start sheet, page adornments, etc.),         used by accounting or resource tracking management tools, or         even stored along with the document as a document level         attribute.  IPP/1.1 does not support the concept of document         level attributes.      "compression" (type3 keyword):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute and the "compression-         supported" attribute (seesection 4.4.32).  The client supplied         "compression" operation attribute identifies the compression         algorithm used on the document data. The following cases exist:         a) If the client omits this attribute, the Printer object MUST            assume that the data is not compressed   (i.e. the Printer            follows the rules below as if the client supplied the            "compression" attribute with a value of 'none').         b) If the client supplies this attribute, but the value is not            supported by the Printer object, i.e., the value is not one            of the values of the Printer object's "compression-            supported" attribute, the Printer object MUST reject the            request, and return the 'client-error-compression-not-            supported' status code. Seesection 3.1.7 for returning            unsupported attributes and values.Hastings, et al.            Standards Track                    [Page 42]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         c) If the client supplies the attribute and the Printer object            supports the attribute value, the Printer object uses the            corresponding decompression algorithm on the document data.         d) If the decompression algorithm fails before the Printer            returns an operation response, the Printer object MUST            reject the request and return the 'client-error-            compression-error' status code.         e) If the decompression algorithm fails after the Printer            returns an operation response, the Printer object MUST abort            the job and add the 'compression-error' value to the job's            "job-state-reasons" attribute.         f) If the decompression algorithm succeeds, the document data            MUST then have the format specified by the job's "document-            format" attribute, if supplied (see "document-format"            operation attribute definition below).      "document-format" (mimeMediaType):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute.  The value of this         attribute identifies the format of the supplied document data.         The following cases exist:         a) If the client does not supply this attribute, the Printer            object assumes that the document data is in the format            defined by the Printer object's "document-format-default"            attribute. (i.e. the Printer follows the rules below as if            the client supplied the "document-format" attribute with a            value equal to the printer's default value).         b) If the client supplies this attribute, but the value is not            supported by the Printer object, i.e., the value is not one            of the values of the Printer object's "document-format-            supported" attribute, the Printer object MUST reject the            request and return the 'client-error-document-format-not-            supported' status code.         c) If the client supplies this attribute and its value is            'application/octet-stream' (i.e. to be auto-sensed, seeSection 4.1.9.1), and the format is not one of the            document-formats that the Printer can auto-sense, and this            check occurs before the Printer returns an operation            response, then the Printer MUST reject the request and            return the  'client-error-document-format-not-supported'            status code.         d) If the client supplies this attribute, and the value is            supported by the Printer object, the Printer is capable of            interpreting the document data.Hastings, et al.            Standards Track                    [Page 43]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         e) If interpreting of the document data fails before the            Printer returns an operation response, the Printer object            MUST reject the request and return the 'client-error-            document-format-error' status code.         f) If interpreting of the document data fails after the Printer            returns an operation response, the Printer object MUST abort            the job and add the 'document-format-error' value to the            job's "job-state-reasons" attribute.      "document-natural-language" (naturalLanguage):         The client OPTIONALLY supplies this attribute.  The Printer         object OPTIONALLY supports this attribute. This attribute         specifies the natural language of the document for those         document-formats that require a specification of the natural         language in order to image the document unambiguously. There         are no particular values required for the Printer object to         support.      "job-k-octets" (integer(0:MAX)):         The client OPTIONALLY supplies this attribute.  The Printer         object OPTIONALLY supports this attribute and the "job-k-         octets-supported" attribute (seesection 4.4.33).  The client         supplied "job-k-octets" operation attribute identifies the         total size of the document(s) in K octets being submitted (seesection 4.3.17.1 for the complete semantics).  If the client         supplies the attribute and the Printer object supports the         attribute, the value of the attribute is used to populate the         Job object's "job-k-octets" Job Description attribute.         For this attribute and the following two attributes ("job-         impressions", and "job-media-sheets"), if the client supplies         the attribute, but the Printer object does not support the         attribute, the Printer object ignores the client-supplied         value.  If the client supplies the attribute and the Printer         supports the attribute, and the value is within the range of         the corresponding Printer object's "xxx-supported" attribute,         the Printer object MUST use the value to populate the Job         object's "xxx" attribute.  If the client supplies the attribute         and the Printer supports the attribute, but the value is         outside the range of the corresponding Printer object's "xxx-         supported" attribute, the Printer object MUST copy the         attribute and its value to the Unsupported Attributes response         group, reject the request, and return the 'client-error-         attributes-or-values-not-supported' status code.  If the client         does not supply the attribute, the Printer object MAY choose to         populate the corresponding Job object attribute depending on         whether the Printer object supports the attribute and is able         to calculate or discern the correct value.Hastings, et al.            Standards Track                    [Page 44]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      "job-impressions" (integer(0:MAX)):         The client OPTIONALLY supplies this attribute.  The Printer         object OPTIONALLY supports this attribute and the "job-         impressions-supported" attribute (seesection 4.4.34).  The         client supplied "job-impressions" operation attribute         identifies the total size in number of impressions of the         document(s) being submitted (seesection 4.3.17.2 for the         complete semantics).         See last paragraph under "job-k-octets".      "job-media-sheets" (integer(0:MAX)):         The client OPTIONALLY supplies this attribute.  The Printer         object OPTIONALLY supports this attribute and the "job-media-         sheets-supported" attribute (seesection 4.4.35).  The client         supplied "job-media-sheets" operation attribute identifies the         total number of media sheets to be produced for this job (seesection 4.3.17.3 for the complete semantics).         See last paragraph under "job-k-octets".   Group 2: Job Template Attributes      The client OPTIONALLY supplies a set of Job Template attributes as      defined insection 4.2.  If the client is not supplying any Job      Template attributes in the request, the client SHOULD omit Group 2      rather than sending an empty group.  However, a Printer object      MUST be able to accept an empty group.   Group 3: Document Content      The client MUST supply the document data to be processed.      In addition to the MANDATORY parameters required for every      operation request, the simplest Print-Job Request consists of just      the "attributes-charset" and "attributes-natural-language"      operation attributes; the "printer-uri" target operation      attribute; the Document Content and nothing else.  In this simple      case, the Printer object:      - creates a new Job object (the Job object contains a single        document),      - stores a generated Job name in the "job-name" attribute in the        natural language and charset requested (seeSection 3.1.4.1) (if        those are supported, otherwise using the Printer object's        default natural language and charset), andHastings, et al.            Standards Track                    [Page 45]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      - at job processing time, uses its corresponding default value        attributes for the supported Job Template attributes that were        not supplied by the client as IPP attribute or embedded        instructions in the document data.3.2.1.2 Print-Job Response   The Printer object MUST return to the client the following sets of   attributes as part of the Print-Job Response:   Group 1: Operation Attributes      Status Message:         In addition to the REQUIRED status code returned in every         response, the response OPTIONALLY includes a "status-message"         (text(255)) and/or a "detailed-status-message" (text(MAX))         operation attribute as described in sections13 and3.1.6.  If         the client supplies unsupported or conflicting Job Template         attributes or values, the Printer object MUST reject or accept         the Print-Job request depending on the whether the client         supplied a 'true' or 'false' value for the "ipp-attribute-         fidelity" operation attribute.  See the Implementer's Guide         [IPP-IIG] for a complete description of the suggested steps for         processing a create request.      Natural Language and Character Set:         The "attributes-charset" and "attributes-natural-language"         attributes as described insection 3.1.4.2.   Group 2: Unsupported Attributes      Seesection 3.1.7 for details on returning Unsupported Attributes.      The value of the "ipp-attribute-fidelity" supplied by the client      does not affect what attributes the Printer object returns in this      group.  The value of "ipp-attribute-fidelity" only affects whether      the Print-Job operation is accepted or rejected.  If the job is      accepted, the client may query the job using the Get-Job-      Attributes operation requesting the unsupported attributes that      were returned in the create response to see which attributes were      ignored (not stored on the Job object) and which attributes were      stored with other (substituted) values.Hastings, et al.            Standards Track                    [Page 46]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Group 3: Job Object Attributes      "job-uri" (uri):         The Printer object MUST return the Job object's URI by         returning the contents of the REQUIRED "job-uri" Job object         attribute.  The client uses the Job object's URI when directing         operations at the Job object.  The Printer object always uses         its configured security policy when creating the new URI.         However, if the Printer object supports more than one URI, the         Printer object also uses information about which URI was used         in the Print-Job Request to generated the new URI so that the         new URI references the correct access channel.  In other words,         if the Print-Job Request comes in over a secure channel, the         Printer object MUST generate a Job URI that uses the secure         channel as well.      "job-id" (integer(1:MAX)):         The Printer object MUST return the Job object's Job ID by         returning the REQUIRED  "job-id" Job object attribute.  The         client uses this "job-id" attribute in conjunction with the         "printer-uri" attribute used in the Print-Job Request when         directing Job operations at the Printer object.      "job-state" (type1 enum):         The Printer object MUST return the Job object's REQUIRED "job-         state" attribute. The value of this attribute (along with the         value of the next attribute:  "job-state-reasons") is taken         from a "snapshot" of the new Job object at some meaningful         point in time (implementation defined) between when the Printer         object receives the Print-Job Request and when the Printer         object returns the response.      "job-state-reasons" (1setOf type2 keyword):         The Printer object MUST return the Job object's REQUIRED "job-         state-reasons" attribute.      "job-state-message" (text(MAX)):         The Printer object OPTIONALLY returns the Job object's OPTIONAL         "job-state-message" attribute.  If the Printer object supports         this attribute then it MUST be returned in the response.  If         this attribute is not returned in the response, the client can         assume that the "job-state-message" attribute is not supported         and will not be returned in a subsequent Job object query.      "number-of-intervening-jobs" (integer(0:MAX)):         The Printer object OPTIONALLY returns the Job object's OPTIONAL         "number-of-intervening-jobs" attribute.  If the Printer object         supports this attribute then it MUST be returned in theHastings, et al.            Standards Track                    [Page 47]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         response.  If this attribute is not returned in the response,         the client can assume that the "number-of-intervening-jobs"         attribute is not supported and will not be returned in a         subsequent Job object query.         Note: Since any printer state information which affects a job's         state is reflected in the "job-state" and "job-state-reasons"         attributes, it is sufficient to return only these attributes         and no specific printer status attributes.   Note: In addition to the MANDATORY parameters required for every   operation response, the simplest response consists of the just the   "attributes-charset" and "attributes-natural-language" operation   attributes and the "job-uri", "job-id", and "job-state" Job Object   Attributes.  In this simplest case, the status code is 'successful-   ok' and there is no "status-message" or "detailed-status-message"   operation attribute.3.2.2 Print-URI Operation   This OPTIONAL operation is identical to the Print-Job operation   (section 3.2.1) except that a client supplies a URI reference to the   document data using the "document-uri" (uri) operation attribute (in   Group 1) rather than including the document data itself.  Before   returning the response, the Printer MUST validate that the Printer   supports the retrieval method (e.g., http, ftp, etc.) implied by the   URI, and MUST check for valid URI syntax.  If the client-supplied URI   scheme is not supported, i.e. the value is not in the Printer   object's "referenced-uri-scheme-supported" attribute, the Printer   object MUST reject the request and return the 'client-error-uri-   scheme-not-supported' status code.   The IPP Printer MAY validate the accessibility of the document as   part of the operation or subsequently.  If the Printer determines an   accessibility problem before returning an operation response, it   rejects the request and returns the 'client-error-document-access-   error' status code.  The Printer MAY also return a specific document   access error code using the "document-access-error" operation   attribute (seesection 3.1.6.4).   If the Printer determines this document accessibility problem after   accepting the request and returning an operation response with one of   the successful status codes, the Printer adds the 'document-access-   error' value to the job's "job-state-reasons" attribute and MAY   populate the job's "job-document-access-errors" Job Description   attribute (seesection 4.3.11).  See The Implementer's Guide [IPP-   IIG] for suggested additional checks.Hastings, et al.            Standards Track                    [Page 48]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   If the Printer object supports this operation, it MUST support the   "reference-uri-schemes-supported" Printer attribute (seesection4.4.27).   It is up to the IPP object to interpret the URI and subsequently   "pull" the document from the source referenced by the URI string.3.2.3 Validate-Job Operation   This REQUIRED operation is similar to the Print-Job operation   (section 3.2.1) except that a client supplies no document data and   the Printer allocates no resources (i.e., it does not create a new   Job object).  This operation is used only to verify capabilities of a   printer object against whatever attributes are supplied by the client   in the Validate-Job request.  By using the Validate-Job operation a   client can validate that an identical Print-Job operation (with the   document data) would be accepted. The Validate-Job operation also   performs the same security negotiation as the Print-Job operation   (seesection 8), so that a client can check that the client and   Printer object security requirements can be met before performing a   Print-Job operation.   The Validate-Job operation does not accept a "document-uri" attribute   in order to allow a client to check that the same Print-URI operation   will be accepted, since the client doesn't send the data with the   Print-URI operation.  The client SHOULD just issue the Print-URI   request.   The Printer object returns the same status codes, Operation   Attributes (Group 1) and Unsupported Attributes (Group 2) as the   Print-Job operation.  However, no Job Object Attributes (Group 3) are   returned, since no Job object is created.3.2.4 Create-Job Operation   This OPTIONAL operation is similar to the Print-Job operation   (section 3.2.1) except that in the Create-Job request, a client does   not supply document data or any reference to document data.  Also,   the client does not supply any of the "document-name", "document-   format", "compression", or "document-natural-language" operation   attributes.  This operation is followed by one or more Send-Document   or Send-URI operations.  In each of those operation requests, the   client OPTIONALLY supplies the "document-name", "document-format",   and "document-natural-language" attributes for each document in the   multi-document Job object.Hastings, et al.            Standards Track                    [Page 49]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   If a Printer object supports the Create-Job operation, it MUST also   support the Send-Document operation and also MAY support the Send-URI   operation.   If the Printer object supports this operation, it MUST support the   "multiple-operation-time-out" Printer attribute (seesection 4.4.31).   If the Printer object supports this operation, then it MUST support   the "multiple-document-jobs-supported" Printer Description attribute   (seesection 4.4.16) and indicate whether or not it supports   multiple-document jobs.   If the Printer object supports this operation and supports multiple   documents in a job, then it MUST support the "multiple-document-   handling" Job Template job attribute with at least one value (seesection 4.2.4) and the associated "multiple-document-handling-   default" and "multiple-document-handling-supported" Job Template   Printer attributes (seesection 4.2).   After the Create-Job operation has completed, the value of the "job-   state" attribute is similar to the "job-state" after a Print-Job,   even though no document-data has arrived.  A Printer MAY set the   'job-data-insufficient' value of the job's "job-state-reason"   attribute to indicate that processing cannot begin until sufficient   data has arrived and set the "job-state" to either 'pending' or   'pending-held'.  A non-spooling printer that doesn't implement the   'pending' job state may even set the "job-state" to 'processing',   even though there is not yet any data to process.  See sections4.3.7   and 4.3.8.3.2.5 Get-Printer-Attributes Operation   This REQUIRED operation allows a client to request the values of the   attributes of a Printer object.   In the request, the client supplies   the set of Printer attribute names and/or attribute group names in   which the requester is interested.  In the response, the Printer   object returns a corresponding attribute set with the appropriate   attribute values filled in.   For Printer objects, the possible names of attribute groups are:      - 'job-template': the subset of the Job Template attributes that        apply to a Printer object (the last two columns of the table inSection 4.2) that the implementation supports for Printer        objects.      - 'printer-description': the subset of the attributes specified inSection 4.4 that the implementation supports for Printer        objects.Hastings, et al.            Standards Track                    [Page 50]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      - 'all': the special group 'all' that includes all attributes that        the implementation supports for Printer objects.   Since a client MAY request specific attributes or named groups, there   is a potential that there is some overlap.  For example, if a client   requests, 'printer-name' and 'all', the client is actually requesting   the "printer-name" attribute twice: once by naming it explicitly, and   once by inclusion in the 'all' group.  In such cases, the Printer   object NEED NOT return each attribute only once in the response even   if it is requested multiple times.  The client SHOULD NOT request the   same attribute in multiple ways.   It is NOT REQUIRED that a Printer object support all attributes   belonging to a group (since some attributes are OPTIONAL).  However,   it is REQUIRED that each Printer object support all group names.3.2.5.1 Get-Printer-Attributes Request   The following sets of attributes are part of the Get-Printer-   Attributes Request:   Group 1: Operation Attributes      Natural Language and Character Set:         The "attributes-charset" and "attributes-natural-language"         attributes as described insection 3.1.4.1.      Target:         The "printer-uri" (uri) operation attribute which is the target         for this operation as described insection 3.1.5.      Requesting User Name:         The "requesting-user-name" (name(MAX)) attribute SHOULD be         supplied by the client as described insection 8.3.      "requested-attributes" (1setOf keyword):         The client OPTIONALLY supplies a set of attribute names and/or         attribute group names in whose values the requester is         interested.  The Printer object MUST support this attribute.         If the client omits this attribute, the Printer MUST respond as         if this attribute had been supplied with a value of 'all'.      "document-format" (mimeMediaType):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute.  This attribute is useful         for a Printer object to determine the set of supported         attribute values that relate to the requested document format.         The Printer object MUST return the attributes and values thatHastings, et al.            Standards Track                    [Page 51]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         it uses to validate a job on a create or Validate-Job operation         in which this document format is supplied. The Printer object         SHOULD return only (1) those attributes that are supported for         the specified format and (2) the attribute values that are         supported for the specified document format.  By specifying the         document format, the client can get the Printer object to         eliminate the attributes and values that are not supported for         a specific document format.  For example, a Printer object         might have multiple interpreters to support both         'application/postscript' (for PostScript) and 'text/plain' (for         text) documents.  However, for only one of those interpreters         might the Printer object be able to support "number-up" with         values of '1', '2', and '4'.  For the other interpreter it         might be able to only support "number-up" with a value of '1'.         Thus a client can use the Get-Printer-Attributes operation to         obtain the attributes and values that will be used to         accept/reject a create job operation.         If the Printer object does not distinguish between different         sets of supported values for each different document format         when validating jobs in the create and Validate-Job operations,         it MUST NOT distinguish between different document formats in         the Get-Printer-Attributes operation. If the Printer object         does distinguish between different sets of supported values for         each different document format specified by the client, this         specialization applies only to the following Printer object         attributes:      - Printer attributes that are Job Template attributes ("xxx-        default" "xxx-supported", and "xxx-ready" in the Table inSection 4.2),      - "pdl-override-supported",      - "compression-supported",      - "job-k-octets-supported",      - "job-impressions-supported",      - "job-media-sheets-supported",      - "printer-driver-installer",      - "color-supported", and      - "reference-uri-schemes-supported"      The values of all other Printer object attributes (including      "document-format-supported") remain invariant with respect to the      client supplied document format (except for new Printer      description attribute as registered according tosection 6.2).      If the client omits this "document-format" operation attribute,      the Printer object MUST respond as if the attribute had been      supplied with the value of the Printer object's "document-format-Hastings, et al.            Standards Track                    [Page 52]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      default" attribute.  It is RECOMMENDED that the client always      supply a value for "document-format", since the Printer object's      "document-format-default" may be 'application/octet-stream', in      which case the returned attributes and values are for the union of      the document formats that the Printer can automatically sense.      For more details, see the description of the 'mimeMediaType'      attribute syntax insection 4.1.9.      If the client supplies a value for the "document-format" Operation      attribute that is not supported by the Printer, i.e., is not among      the values of the Printer object's "document-format-supported"      attribute, the Printer object MUST reject the operation and return      the 'client-error-document-format-not-supported' status code.3.2.5.2 Get-Printer-Attributes Response   The Printer object returns the following sets of attributes as part   of the Get-Printer-Attributes Response:   Group 1: Operation Attributes      Status Message:        In addition to the REQUIRED status code returned in every        response, the response OPTIONALLY includes a "status-message"        (text(255)) and/or a "detailed-status-message" (text(MAX))        operation attribute as described in sections13 and  3.1.6.      Natural Language and Character Set:        The "attributes-charset" and "attributes-natural-language"        attributes as described insection 3.1.4.2.   Group 2: Unsupported Attributes      Seesection 3.1.7 for details on returning Unsupported Attributes.      The response NEED NOT contain the "requested-attributes" operation      attribute with any supplied values (attribute keywords) that were      requested by the client but are not supported by the IPP object.      If the Printer object does return unsupported attributes      referenced in the "requested-attributes" operation attribute and      that attribute included group names, such as 'all', the      unsupported attributes MUST NOT include attributes described in      the standard but not supported by the implementation.Hastings, et al.            Standards Track                    [Page 53]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Group 3: Printer Object Attributes      This is the set of requested attributes and their current values.      The Printer object ignores (does not respond with) any requested      attribute which is not supported.  The Printer object MAY respond      with a subset of the supported attributes and values, depending on      the security policy in force.  However, the Printer object MUST      respond with the 'unknown' value for any supported attribute      (including all REQUIRED attributes) for which the Printer object      does not know the value.  Also the Printer object MUST respond      with the 'no-value' for any supported attribute (including all      REQUIRED attributes) for which the system administrator has not      configured a value.  See the description of the "out-of-band"      values in the beginning ofSection 4.1.3.2.6 Get-Jobs Operation   This REQUIRED operation allows a client to retrieve the list of Job   objects belonging to the target Printer object.  The client may also   supply a list of Job attribute names and/or attribute group names.  A   group of Job object attributes will be returned for each Job object   that is returned.   This operation is similar to the Get-Job-Attributes operation, except   that this Get-Jobs operation returns attributes from possibly more   than one object.3.2.6.1 Get-Jobs Request   The client submits the Get-Jobs request to a Printer object.   The following groups of attributes are part of the Get-Jobs Request:   Group 1: Operation Attributes      Natural Language and Character Set:         The "attributes-charset" and "attributes-natural-language"         attributes as described insection 3.1.4.1.      Target:         The "printer-uri" (uri) operation attribute which is the target         for this operation as described insection 3.1.5.      Requesting User Name:         The "requesting-user-name" (name(MAX)) attribute SHOULD be         supplied by the client as described insection 8.3.Hastings, et al.            Standards Track                    [Page 54]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      "limit" (integer(1:MAX)):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute. It is an integer value that         determines the maximum number of jobs that a client will         receive from the Printer even if "which-jobs" or "my-jobs"         constrain which jobs are returned.  The limit is a "stateless         limit" in that if the value supplied by the client is 'N', then         only the first 'N' jobs are returned in the Get-Jobs Response.         There is no mechanism to allow for the next 'M' jobs after the         first 'N' jobs.  If the client does not supply this attribute,         the Printer object responds with all applicable jobs.      "requested-attributes" (1setOf type2 keyword):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute.  It is a set of Job         attribute names and/or attribute groups names in whose values         the requester is interested.  This set of attributes is         returned for each Job object that is returned.  The allowed         attribute group names are the same as those defined in the         Get-Job-Attributes operation insection 3.3.4.  If the client         does not supply this attribute, the Printer MUST respond as if         the client had supplied this attribute with two values: 'job-         uri' and 'job-id'.      "which-jobs" (type2 keyword):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute.  It indicates which Job         objects MUST be returned by the Printer object. The values for         this attribute are:      'completed': This includes any Job object whose state is         'completed', 'canceled', or 'aborted'.      'not-completed': This includes any Job object whose state is         'pending', 'processing', 'processing-stopped', or 'pending-         held'.         A Printer object MUST support both values.  However, if the         implementation does not keep jobs in the 'completed',         'canceled', and 'aborted' states, then it returns no jobs when         the 'completed' value is supplied.         If a client supplies some other value, the Printer object MUST         copy the attribute and the unsupported value to the Unsupported         Attributes response group, reject the request, and return the         'client-error-attributes-or-values-not-supported' status code.Hastings, et al.            Standards Track                    [Page 55]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         If the client does not supply this attribute, the Printer         object MUST respond as if the client had supplied the attribute         with a value of 'not-completed'.      "my-jobs" (boolean):         The client OPTIONALLY supplies this attribute.  The Printer         object MUST support this attribute.  It indicates whether jobs         from all users or just the jobs submitted by the requesting         user of this request MUST be considered as candidate jobs to be         returned by the Printer object.  If the client does not supply         this attribute, the Printer object MUST respond as if the         client had supplied the attribute with a value of 'false',         i.e., jobs from all users.  The means for authenticating the         requesting user and matching the jobs is described insection8.3.2.6.2 Get-Jobs Response   The Printer object returns all of the Job objects up to the number   specified by the "limit" attribute that match the criteria as defined   by the attribute values supplied by the client in the request.  It is   possible that no Job objects are returned since there may literally   be no Job objects at the Printer, or there may be no Job objects that   match the criteria supplied by the client.  If the client requests   any Job attributes at all, there is a set of Job Object Attributes   returned for each Job object.   It is not an error for the Printer to return 0 jobs. If the response   returns 0 jobs because there are no jobs matching the criteria, and   the request would have returned 1 or more jobs with a status code of   'successful-ok' if there had been jobs matching the criteria, then   the status code for 0 jobs MUST be 'successful-ok'.   Group 1: Operation Attributes      Status Message:        In addition to the REQUIRED status code returned in every        response, the response OPTIONALLY includes a "status-message"        (text(255)) and/or a "detailed-status-message" (text(MAX))        operation attribute as described in sections13 and3.1.6.      Natural Language and Character Set:        The "attributes-charset" and "attributes-natural-language"        attributes as described insection 3.1.4.2.Hastings, et al.            Standards Track                    [Page 56]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Group 2: Unsupported Attributes      Seesection 3.1.7 for details on returning Unsupported Attributes.      The response NEED NOT contain the "requested-attributes" operation      attribute with any supplied values (attribute keywords) that were      requested by the client but are not supported by the IPP object.      If the Printer object does return unsupported attributes      referenced in the "requested-attributes" operation attribute and      that attribute included group names, such as 'all', the      unsupported attributes MUST NOT include attributes described in      the standard but not supported by the implementation.   Groups 3 to N: Job Object Attributes      The Printer object responds with one set of Job Object Attributes      for each returned Job object.  The Printer object ignores (does      not respond with) any requested attribute or value which is not      supported or which is restricted by the security policy in force,      including whether the requesting user is the user that submitted      the job (job originating user) or not (seesection 8).  However,      the Printer object MUST respond with the 'unknown' value for any      supported attribute (including all REQUIRED attributes) for which      the Printer object does not know the value, unless it would      violate the security policy.  See the description of the "out-of-      band" values in the beginning ofSection 4.1.      Jobs are returned in the following order:      - If the client requests all 'completed' Jobs (Jobs in the        'completed', 'aborted', or 'canceled' states), then the Jobs are        returned newest to oldest (with respect to actual completion        time)      - If the client requests all 'not-completed' Jobs (Jobs in the        'pending', 'processing', 'pending-held', and 'processing-        stopped' states), then Jobs are returned in relative        chronological order of expected time to complete (based on        whatever scheduling algorithm is configured for the Printer        object).3.2.7 Pause-Printer Operation   This OPTIONAL operation allows a client to stop the Printer object   from scheduling jobs on all its devices.  Depending on   implementation, the Pause-Printer operation MAY also stop the Printer   from processing the current job or jobs.  Any job that is currently   being printed is either stopped as soon as the implementation permitsHastings, et al.            Standards Track                    [Page 57]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   or is completed, depending on implementation.  The Printer object   MUST still accept create operations to create new jobs, but MUST   prevent any jobs from entering the 'processing' state.   If the Pause-Printer operation is supported, then the Resume-Printer   operation MUST be supported, and vice-versa.   The IPP Printer stops the current job(s) on its device(s) that were   in the 'processing' or 'processing-stopped' states as soon as the   implementation permits.  If the implementation will take appreciable   time to stop, the IPP Printer adds the 'moving-to-paused' value to   the Printer object's "printer-state-reasons" attribute (seesection4.4.12).  When the device(s) have all stopped, the IPP Printer   transitions the Printer object to the 'stopped' state, removes the   'moving-to-paused' value, if present, and adds the 'paused' value to   the Printer object's "printer-state-reasons" attribute.   When the current job(s) complete that were in the 'processing' state,   the IPP Printer transitions them to the 'completed' state.  When the   current job(s) stop in mid processing that were in the 'processing'   state, the IPP Printer transitions them to the 'processing-stopped'   state and adds the 'printer-stopped' value to the job's "job-state-   reasons" attribute.   For any jobs that are 'pending' or 'pending-held', the 'printer-   stopped' value of the jobs' "job-state-reasons" attribute also   applies.  However, the IPP Printer NEED NOT update those jobs' "job-   state-reasons" attributes and only need return the 'printer-stopped'   value when those jobs are queried (so-called "lazy evaluation").   Whether the Pause-Printer operation affects jobs that were submitted   to the device from other sources than the IPP Printer object in the   same way that the Pause-Printer operation affects jobs that were   submitted to the IPP Printer object using IPP, depends on   implementation, i.e., on whether the IPP protocol is being used as a   universal management protocol or just to manage IPP jobs,   respectively.   The IPP Printer MUST accept the request in any state and transition   the Printer to the indicated new "printer-state" before returning as   follows:Hastings, et al.            Standards Track                    [Page 58]

RFC 2911              IPP/1.1: Model and Semantics        September 2000     Current        New      "printer   IPP Printer's response status    "printer-    "printer-   -state-          code and action:     state"       state"    reasons"  'idle'       'stopped'    'paused'  'successful-ok'  'processing' 'processing' 'moving-  OPTION 1: 'successful-ok';                              to-       Later, when all output has                              paused'   stopped, the "printer-state"                                        becomes 'stopped', and the                                        'paused' value replaces the                                        'moving-to-paused' value in the                                        "printer-state-reasons"                                        attribute  'processing' 'stopped'    'paused'  OPTION 2: 'successful-ok';                                        all device output stopped                                        immediately  'stopped'    'stopped'    'paused'  'successful-ok'   Access Rights: The authenticated user (seesection 8.3) performing   this operation must be an operator or administrator of the Printer   object (see Sections1 and8.5).   Otherwise, the IPP Printer MUST   reject the operation and return:  'client-error-forbidden', 'client-   error-not-authenticated', or 'client-error-not-authorized' as   appropriate.3.2.7.1 Pause-Printer Request   The following groups of attributes are part of the Pause-Printer   Request:   Group 1: Operation Attributes      Natural Language and Character Set:        The "attributes-charset" and "attributes-natural-language"        attributes as described insection 3.1.4.1.      Target:        The "printer-uri" (uri) operation attribute which is the target        for this operation as described insection 3.1.5.      Requesting User Name:        The "requesting-user-name" (name(MAX)) attribute SHOULD be        supplied by the client as described insection 8.3.Hastings, et al.            Standards Track                    [Page 59]

RFC 2911              IPP/1.1: Model and Semantics        September 20003.2.7.2 Pause-Printer Response   The following groups of attributes are part of the Pause-Printer   Response:   Group 1: Operation Attributes      Status Message:        In addition to the REQUIRED status code returned in every        response, the response OPTIONALLY includes a "status-message"        (text(255)) and/or a "detailed-status-message" (text(MAX))        operation attribute as described in sections13 and  3.1.6.      Natural Language and Character Set:        The "attributes-charset" and "attributes-natural-language"        attributes as described insection 3.1.4.2.   Group 2: Unsupported Attributes      Seesection 3.1.7 for details on returning Unsupported Attributes.3.2.8 Resume-Printer Operation   This operation allows a client to resume the Printer object   scheduling jobs on all its devices.  The Printer object MUST remove   the 'paused' and 'moving-to-paused' values from the Printer object's   "printer-state-reasons" attribute, if present.  If there are no other   reasons to keep a device paused (such as media-jam), the IPP Printer   is free to transition itself to the 'processing' or 'idle' states,   depending on whether there are jobs to be processed or not,   respectively, and the device(s) resume processing jobs.   If the Pause-Printer operation is supported, then the Resume-Printer   operation MUST be supported, and vice-versa.   The IPP Printer removes the 'printer-stopped' value from any job's   "job-state-reasons" attributes contained in that Printer.   The IPP Printer MUST accept the request in any state, transition the   Printer object to the indicated new state as follows:Hastings, et al.            Standards Track                    [Page 60]

RFC 2911              IPP/1.1: Model and Semantics        September 2000     Current    New "printer-  IPP Printer's response status code and    "printer-      state"                     action:      state"   'idle'       'idle'         'successful-ok'   'processing' 'processing'   'successful-ok'   'stopped'    'processing'   'successful-ok';                               when there are jobs to be processed   'stopped'    'idle'         'successful-ok';                               when there are no jobs to be processed.   Access Rights: The authenticated user (seesection 8.3) performing   this operation must be an operator or administrator of the Printer   object (see Sections1 and8.5).  Otherwise, the IPP Printer MUST   reject the operation and return:  'client-error-forbidden', 'client-   error-not-authenticated', or 'client-error-not-authorized' as   appropriate.   The Resume-Printer Request and Resume-Printer Response have the same   attribute groups and attributes as the Pause-Printer operation (see   sections3.2.7.1 and3.2.7.2).3.2.9 Purge-Jobs Operation   This OPTIONAL operation allows a client to remove all jobs from an   IPP Printer object, regardless of their job states, including jobs in   the Printer object's Job History (seeSection 4.3.7.2).  After a   Purge-Jobs operation has been performed, a Printer object MUST return   no jobs in subsequent Get-Job-Attributes and Get-Jobs responses   (until new jobs are submitted).   Whether the Purge-Jobs (and Get-Jobs) operation affects jobs that   were submitted to the device from other sources than the IPP Printer   object in the same way that the Purge-Jobs operation affects jobs   that were submitted to the IPP Printer object using IPP, depends on   implementation, i.e., on whether the IPP protocol is being used as a   universal management protocol or just to manage IPP jobs,   respectively.   Note:  if an operator wants to cancel all jobs without clearing out   the Job History, the operator uses the Cancel-Job operation on each   job instead of using the Purge-Jobs operation.   The Printer object MUST accept this operation in any state and   transition the Printer object to the 'idle' state.Hastings, et al.            Standards Track                    [Page 61]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Access Rights: The authenticated user (seesection 8.3) performing   this operation must be an operator or administrator of the Printer   object (see Sections1 and8.5).  Otherwise, the IPP object MUST   reject the operation and return: client-error-forbidden, client-   error-not-authenticated, and client-error-not-authorized as   appropriate.   The Purge-Jobs Request and Purge-Jobs Response have the same   attribute groups and attributes as the Pause-Printer operation (see   sections3.2.7.1 and3.2.7.2).3.3 Job Operations   All Job operations are directed at Job objects.  A client MUST always   supply some means of identifying the Job object in order to identify   the correct target of the operation.  That job identification MAY   either be a single Job URI or a combination of a Printer URI with a   Job ID.  The IPP object implementation MUST support both forms of   identification for every job.3.3.1 Send-Document Operation   This OPTIONAL operation allows a client to create a multi-document   Job object that is initially "empty" (contains no documents).  In the   Create-Job response, the Printer object returns the Job object's URI   (the "job-uri" attribute) and the Job object's 32-bit identifier (the   "job-id" attribute).  For each new document that the client desires   to add, the client uses a Send-Document operation.  Each Send-   Document Request contains the entire stream of document data for one   document.   If the Printer supports this operation but does not support multiple   documents per job, the Printer MUST reject subsequent Send-Document   operations supplied with data and return the 'server-error-multiple-   document-jobs-not-supported'.  However, the Printer MUST accept the   first document with a 'true' or 'false' value for the "last-document"   operation attribute (see below), so that clients MAY always submit   one document jobs with a 'false' value for "last-document" in the   first Send-Document and a 'true' for "last-document" in the second   Send-Document (with no data).   Since the Create-Job and the send operations (Send-Document or Send-   URI operations) that follow could occur over an arbitrarily long   period of time for a particular job, a client MUST send another send   operation within an IPP Printer defined minimum time interval after   the receipt of the previous request for the job.  If a Printer object   supports the Create-Job and Send-Document operations, the Printer   object MUST support the "multiple-operation-time-out" attribute (seeHastings, et al.            Standards Track                    [Page 62]

RFC 2911              IPP/1.1: Model and Semantics        September 2000section 4.4.31).  This attribute indicates the minimum number of   seconds the Printer object will wait for the next send operation   before taking some recovery action.   An IPP object MUST recover from an errant client that does not supply   a send operation, sometime after the minimum time interval specified   by the Printer object's "multiple-operation-time-out" attribute.   Such recovery MAY include any of the following or other recovery   actions:      1. Assume that the Job is an invalid job, start the process of         changing the job state to 'aborted', add the 'aborted-by-         system' value to the job's "job-state-reasons" attribute (seesection 4.3.8), and clean up all resources associated with the         Job.  In this case, if another send operation is finally         received, the Printer responds with an "client-error-not-         possible" or "client-error-not-found" depending on whether or         not the Job object is still around when the send operation         finally arrives.      2. Assume that the last send operation received was in fact the         last document (as if the "last-document" flag had been set to         'true'), close the Job object, and proceed to process it (i.e.,         move the Job's state to 'pending').      3. Assume that the last send operation received was in fact the         last document, close the Job, but move it to the 'pending-held'         and add the 'submission-interrupted' value to the job's "job-         state-reasons" attribute (seesection 4.3.8).  This action         allows the user or an operator to determine whether to continue         processing the Job by moving it back to the 'pending' state         using the Release-Job operation (seesection 3.3.6) or to         cancel the job using the Cancel-Job operation (seesection3.3.3).   Each implementation is free to decide the "best" action to take   depending on local policy, whether any documents have been added,   whether the implementation spools jobs or not,  and/or any other   piece of information available to it.  If the choice is to abort the   Job object, it is possible that the Job object may already have been   processed to the point that some media sheet pages have been printed.   Access Rights: The authenticated user (seesection 8.3) performing   this operation must either be the job owner (as determined in the   Create-Job operation) or an operator or administrator of the Printer   object (see Sections1 and8.5).  Otherwise, the IPP object MUST   reject the operation and return: 'client-error-forbidden', 'client-   error-not-authenticated', or 'client-error-not-authorized' as   appropriate.Hastings, et al.            Standards Track                    [Page 63]

RFC 2911              IPP/1.1: Model and Semantics        September 20003.3.1.1 Send-Document Request   The following attribute sets are part of the Send-Document Request:   Group 1: Operation Attributes      Natural Language and Character Set:        The "attributes-charset" and "attributes-natural-language"        attributes as described insection 3.1.4.1.      Target:        Either (1) the "printer-uri" (uri) plus "job-id"        (integer(1:MAX))or (2) the "job-uri" (uri) operation        attribute(s) which define the target for this operation as        described insection 3.1.5.      Requesting User Name:        The "requesting-user-name" (name(MAX)) attribute SHOULD be        supplied by the client as described insection 8.3.      "document-name" (name(MAX)):        The client OPTIONALLY supplies this attribute.  The Printer        object MUST support this attribute.  It contains the client        supplied document name.  The document name MAY be different than        the Job name.  It might be helpful, but NEED NOT be unique        across multiple documents in the same Job.  Typically, the        client software automatically supplies the document name on        behalf of the end user by using a file name or an application        generated name.  See the description of the "document-name"        operation attribute in the Print-Job Request (section 3.2.1.1)        for more information about this attribute.      "compression" (type3 keyword):        See the description of "compression" for the Print-Job operation        inSection 3.2.1.1.      "document-format" (mimeMediaType):        See the description of "document-format" for the Print-Job        operation inSection 3.2.1.1.      "document-natural-language" (naturalLanguage):        The client OPTIONALLY supplies this attribute.  The Printer        object OPTIONALLY supports this attribute.  This attribute        specifies the natural language of the document for those        document-formats that require a specification of the natural        language in order to image the document unambiguously.  There        are no particular values required for the Printer object to        support.Hastings, et al.            Standards Track                    [Page 64]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      "last-document" (boolean):        The client MUST supply this attribute.  The Printer object MUST        support this attribute. It is a boolean flag that is set to        'true' if this is the last document for the Job, 'false'        otherwise.   Group 2: Document Content      The client MUST supply the document data if the "last-document"      flag is set to 'false'.  However, since a client might not know      that the previous document sent with a Send-Document (or Send-URI)      operation was the last document (i.e., the "last-document"      attribute was set to 'false'), it is legal to send a Send-Document      request with no document data where the "last-document" flag is      set to 'true'.  Such a request MUST NOT increment the value of the      Job object's "number-of-documents" attribute, since no real      document was added to the job.  It is not an error for a client to      submit a job with no actual document data, i.e., only a single      Create-Job and Send-Document request with a "last-document"      operation attribute set to 'true' with no document data.3.3.1.2 Send-Document Response   The following sets of attributes are part of the Send-Document   Response:   Group 1: Operation Attributes      Status Message:         In addition to the REQUIRED status code returned in every         response, the response OPTIONALLY includes a "status-message"         (text(255)) and/or a "detailed-status-message" (text(MAX))         operation attribute as described in sections13 and3.1.6.      Natural Language and Character Set:         The "attributes-charset" and "attributes-natural-language"         attributes as described insection 3.1.4.2.   Group 2: Unsupported Attributes      Seesection 3.1.7 for details on returning Unsupported Attributes.   Group 3: Job Object Attributes      This is the same set of attributes as described in the Print-Job      response (seesection 3.2.1.2).Hastings, et al.            Standards Track                    [Page 65]

RFC 2911              IPP/1.1: Model and Semantics        September 20003.3.2 Send-URI Operation   This OPTIONAL operation is identical to the Send-Document operation   (seesection 3.3.1) except that a client MUST supply a URI reference   ("document-uri" operation attribute) rather than the document data   itself.  If a Printer object supports this operation, clients can use   both Send-URI or Send-Document operations to add new documents to an   existing multi-document Job object.  However, if a client needs to   indicate that the previous Send-URI or Send-Document was the last   document,  the client MUST use the Send-Document operation with no   document data and the "last-document" flag set to 'true' (rather than   using a Send-URI operation with no "document-uri" operation   attribute).   If a Printer object supports this operation, it MUST also support the   Print-URI operation (seesection 3.2.2).   The Printer object MUST validate the syntax and URI scheme of the   supplied URI before returning a response, just as in the Print-URI   operation.  The IPP Printer MAY validate the accessibility of the   document as part of the operation or subsequently (seesection3.2.2).3.3.3 Cancel-Job Operation   This REQUIRED operation allows a client to cancel a Print Job from   the time the job is created up to the time it is completed, canceled,   or aborted.  Since a Job might already be printing by the time a   Cancel-Job is received, some media sheet pages might be printed   before the job is actually terminated.   The IPP object MUST accept or reject the request based on the job's   current state and transition the job to the indicated new state as   follows:Hastings, et al.            Standards Track                    [Page 66]

RFC 2911              IPP/1.1: Model and Semantics        September 2000       Current "job-    New "job-     IPP object's response status           state"         state"             code and action:      'pending'       'canceled'     'successful-ok'      'pending-held'  'canceled'     'successful-ok'      'processing'    'canceled'     'successful-ok'      'processing'    'processing'   'successful-ok'  See Rule 1      'processing'    'processing'   'client-error-not-possible'                                     See Rule 2      'processing-    'canceled'     'successful-ok'      stopped'      'processing-    'processing-   'successful-ok'  See Rule 1      stopped'        stopped'      'processing-    'processing-   'client-error-not-possible'      stopped'        stopped'       See Rule 2      'completed'     'completed'    'client-error-not-possible'      'canceled'      'canceled'     'client-error-not-possible'      'aborted'       'aborted'      'client-error-not-possible'   Rule 1:  If the implementation requires some measurable time to   cancel the job in the 'processing' or 'processing-stopped' job   states, the IPP object MUST add the 'processing-to-stop-point' value   to the job's "job-state-reasons" attribute and then transition the   job to the 'canceled' state when the processing ceases (seesection4.3.8).   Rule 2:  If the Job object already has the 'processing-to-stop-point'   value in its "job-state-reasons" attribute, then the Printer object   MUST reject a Cancel-Job operation.   Access Rights: The authenticated user (seesection 8.3) performing   this operation must either be the job owner or an operator or   administrator of the Printer object (see Sections1 and8.5).   Otherwise, the IPP object MUST reject the operation and return:    'client-error-forbidden', 'client-error-not-authenticated', or   'client-error-not-authorized' as appropriate.3.3.3.1 Cancel-Job Request   The following groups of attributes are part of the Cancel-Job   Request:   Group 1: Operation Attributes      Natural Language and Character Set:         The "attributes-charset" and "attributes-natural-language"         attributes as described insection 3.1.4.1.Hastings, et al.            Standards Track                    [Page 67]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      Target:         Either (1) the "printer-uri" (uri) plus "job-id"         (integer(1:MAX))or (2) the "job-uri" (uri) operation         attribute(s) which define the target for this operation as         described insection 3.1.5.      Requesting User Name:         The "requesting-user-name" (name(MAX)) attribute SHOULD be         supplied by the client as described insection 8.3.      "message" (text(127)):         The client OPTIONALLY supplies this attribute.  The Printer         object OPTIONALLY supports this attribute. It is a message to         the operator.  This "message" attribute is not the same as the         "job-message-from-operator" attribute.  That attribute is used         to report a message from the operator to the end user that         queries that attribute.  This "message" operation attribute is         used to send a message from the client to the operator along         with the operation request.  It is an implementation decision         of how or where to display this message to the operator (if at         all).3.3.3.2 Cancel-Job Response   The following sets of attributes are part of the Cancel-Job Response:   Group 1: Operation Attributes      Status Message:         In addition to the REQUIRED status code returned in every         response, the response OPTIONALLY includes a "status-message"         (text(255)) and/or a "detailed-status-message" (text(MAX))         operation attribute as described in sections13 and3.1.6.      Natural Language and Character Set:         The "attributes-charset" and "attributes-natural-language"         attributes as described insection 3.1.4.2.   Group 2: Unsupported Attributes      Seesection 3.1.7 for details on returning Unsupported Attributes.   Once a successful response has been sent, the implementation   guarantees that the Job will eventually end up in the 'canceled'   state. Between the time of the Cancel-Job operation is accepted and   when the job enters the 'canceled' job-state (seesection 4.3.7), the   "job-state-reasons" attribute SHOULD contain the 'processing-to-   stop-point'Hastings, et al.            Standards Track                    [Page 68]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   value which indicates to later queries that although the Job might   still be 'processing', it will eventually end up in the   'canceled' state, not the 'completed' state.3.3.4 Get-Job-Attributes Operation   This REQUIRED operation allows a client to request the values of   attributes of a Job object and it is almost identical to the Get-   Printer-Attributes operation (seesection 3.2.5).  The only   differences are that the operation is directed at a Job object rather   than a Printer object, there is no "document-format" operation   attribute used when querying a Job object, and the returned attribute   group is a set of Job object attributes rather than a set of Printer   object attributes.   For Jobs, the possible names of attribute groups are:      - 'job-template': the subset of the Job Template attributes that        apply to a Job object (the first column of the table inSection4.2) that the implementation supports for Job objects.      - 'job-description': the subset of the Job Description attributes        specified inSection 4.3 that the implementation supports for        Job objects.      - 'all': the special group 'all' that includes all attributes that        the implementation supports for Job objects.   Since a client MAY request specific attributes or named groups, there   is a potential that there is some overlap.  For example, if a client   requests, 'job-name' and 'job-description', the client is actually   requesting the "job-name" attribute once by naming it explicitly, and   once by inclusion in the 'job-description' group.  In such cases, the   Printer object NEED NOT return the attribute only once in the   response even if it is requested multiple times.  The client SHOULD   NOT request the same attribute in multiple ways.   It is NOT REQUIRED that a Job object support all attributes belonging   to a group (since some attributes are OPTIONAL).  However it is   REQUIRED that each Job object support all these group names.3.3.4.1 Get-Job-Attributes Request   The following groups of attributes are part of the Get-Job-Attributes   Request when the request is directed at a Job object:Hastings, et al.            Standards Track                    [Page 69]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Group 1: Operation Attributes      Natural Language and Character Set:        The "attributes-charset" and "attributes-natural-language"        attributes as described insection 3.1.4.1.      Target:        Either (1) the "printer-uri" (uri) plus "job-id"        (integer(1:MAX)) or (2) the "job-uri" (uri) operation        attribute(s) which define the target for this operation as        described insection 3.1.5.      Requesting User Name:        The "requesting-user-name" (name(MAX)) attribute SHOULD be        supplied by the client as described insection 8.3.      "requested-attributes" (1setOf keyword):        The client OPTIONALLY supplies this attribute.  The IPP object        MUST support this attribute.   It is a set of attribute names        and/or attribute group names in whose values the requester is        interested.  If the client omits this attribute, the IPP object        MUST respond as if this attribute had been supplied with a value        of 'all'.3.3.4.2 Get-Job-Attributes Response   The Printer object returns the following sets of attributes as part   of the Get-Job-Attributes Response:   Group 1: Operation Attributes      Status Message:         In addition to the REQUIRED status code returned in every         response, the response OPTIONALLY includes a "status-message"         (text(255)) and/or a "detailed-status-message" (text(MAX))         operation attribute as described in sections13 and3.1.6.      Natural Language and Character Set:         The "attributes-charset" and "attributes-natural-language"         attributes as described insection 3.1.4.2.  The "attributes-         natural-language" MAY be the natural language of the Job         object, rather than the one requested.   Group 2: Unsupported Attributes      Seesection 3.1.7 for details on returning Unsupported Attributes.Hastings, et al.            Standards Track                    [Page 70]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      The response NEED NOT contain the "requested-attributes" operation      attribute with any supplied values (attribute keywords) that were      requested by the client but are not supported by the IPP object.      If the Printer object does return unsupported attributes      referenced in the "requested-attributes" operation attribute and      that attribute included group names, such as 'all', the      unsupported attributes MUST NOT include attributes described in      the standard but not supported by the implementation.   Group 3: Job Object Attributes      This is the set of requested attributes and their current values.      The IPP object ignores (does not respond with) any requested      attribute or value which is not supported or which is restricted      by the security policy in force, including whether the requesting      user is the user that submitted the job (job originating user) or      not (seesection 8).  However, the IPP object MUST respond with      the 'unknown' value for any supported attribute (including all      REQUIRED attributes) for which the IPP object does not know the      value, unless it would violate the security policy.  See the      description of the "out-of-band" values in the beginning ofSection 4.1.3.3.5 Hold-Job Operation   This OPTIONAL operation allows a client to hold a pending job in the   queue so that it is not eligible for scheduling.  If the Hold-Job   operation is supported, then the Release-Job operation MUST be   supported, and vice-versa.  The OPTIONAL "job-hold-until" operation   attribute allows a client to specify whether to hold the job   indefinitely or until a specified time period, if supported.   The IPP object MUST accept or reject the request based on the job's   current state and transition the job to the indicated new state as   follows:Hastings, et al.            Standards Track                    [Page 71]

RFC 2911              IPP/1.1: Model and Semantics        September 2000        Current "job-     New "job-state"   IPP object's response status            state"                                 code and action:      'pending'         'pending-held'     'successful-ok'  See Rule 1      'pending'         'pending'          'successful-ok'  See Rule 2      'pending-held'    'pending-held'     'successful-ok'  See Rule 1      'pending-held'    'pending'          'successful-ok'  See Rule 2      'processing'      'processing'       'client-error-not-possible'      'processing-      'processing-       'client-error-not-possible'      stopped'          stopped'      'completed'       'completed'        'client-error-not-possible'      'canceled'        'canceled'         'client-error-not-possible'      'aborted'         'aborted'          'client-error-not-possible'   Rule 1:  If the implementation supports multiple reasons for a job to   be in the 'pending-held' state, the IPP object MUST add the 'job-   hold-until-specified' value to the job's "job-state-reasons"   attribute.   Rule 2:  If the IPP object supports the "job-hold-until" operation   attribute, but the specified time period has already started (or is   the 'no-hold' value) and there are no other reasons to hold the job,   the IPP object MUST make the job be a candidate for processing   immediately (seeSection 4.2.2) by putting the job in the 'pending'   state.   Note:  In order to keep the Hold-Job operation simple, such a request   is rejected when the job is in the 'processing' or 'processing-   stopped' states.  If an operation is needed to hold jobs while in   these states, it will be added as an additional operation, rather   than overloading the Hold-Job operation.  Then it is clear to clients   by querying the Printer object's "operations-supported" (seeSection4.4.15) and the Job object's "job-state" (seeSection 4.3.7)   attributes which operations are possible.   Access Rights: The authenticated user (seesection 8.3) performing   this operation must either be the job owner or an operator or   administrator of the Printer object (see Sections1 and8.5).   Otherwise, the IPP object MUST reject the operation and return:   'client-error-forbidden', 'client-error-not-authenticated', or   'client-error-not-authorized' as appropriate.3.3.5.1 Hold-Job Request   The groups and operation attributes are the same as for a Cancel-Job   request (seesection 3.3.3.1), with the addition of the following   Group 1 Operation attribute:Hastings, et al.            Standards Track                    [Page 72]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      "job-hold-until" (type3 keyword | name(MAX)):         The client OPTIONALLY supplies this Operation attribute.  The         IPP object MUST support this operation attribute in a Hold-Job         request, if it supports the "job-hold-until" Job template         attribute in create operations.  Seesection 4.2.2.  The IPP         object SHOULD support the "job-hold-until" Job Template         attribute for use in job create operations with at least the         'indefinite' value, if it supports the Hold-Job operation.         Otherwise, a client cannot create a job and hold it immediately         (without picking some supported time period in the future).         If supplied and supported as specified in the Printer's "job-         hold-until-supported" attribute, the IPP object copies the         supplied operation attribute to the Job object, replacing the         job's previous "job-hold-until" attribute, if present, and         makes the job a candidate for scheduling during the supplied         named time period.         If supplied, but either the "job-hold-until" Operation         attribute itself or the value supplied is not supported, the         IPP object accepts the request, returns the unsupported         attribute or value in the Unsupported Attributes Group         according tosection 3.1.7, returns the 'successful-ok-         ignored-or-substituted-attributes, and holds the job         indefinitely until a client performs a subsequent Release-Job         operation.         If the client (1) supplies a value that specifies a time period         that has already started or the 'no-hold' value (meaning don't         hold the job) and (2) the IPP object supports the "job-hold-         until" operation attribute and there are no other reasons to         hold the job, the IPP object MUST accept the operation and make         the job be a candidate for processing immediately (seeSection4.2.2).         If the client does not supply a "job-hold-until" Operation         attribute in the request, the IPP object MUST populate the job         object with a "job-hold-until" attribute with the 'indefinite'         value (if IPP object supports the "job-hold-until" attribute)         and hold the job indefinitely, until a client performs a         Release-Job operation.3.3.5.2 Hold-Job Response   The groups and attributes are the same as for a Cancel-Job response   (seesection 3.3.3.2).Hastings, et al.            Standards Track                    [Page 73]

RFC 2911              IPP/1.1: Model and Semantics        September 20003.3.6 Release-Job Operation   This OPTIONAL operation allows a client to release a previously held   job so that it is again eligible for scheduling.  If the Hold-Job   operation is supported, then the Release-Job operation MUST be   supported, and vice-versa.   This operation removes the "job-hold-until" job attribute, if   present, from the job object that had been supplied in the create or   most recent Hold-Job or Restart-Job operation and removes its effect   on the job.  The IPP object MUST remove the 'job-hold-until-   specified' value from the job's "job-state-reasons" attribute, if   present.  Seesection 4.3.8.   The IPP object MUST accept or reject the request based on the job's   current state and transition the job to the indicated new state as   follows:        Current "job-   New "job-state"    IPP object's response status           state"                                code and action:      'pending'        'pending'        'successful-ok'                                         No effect on the job.      'pending-held'   'pending-held'   'successful-ok'  See Rule 1      'pending-held'   'pending'        'successful-ok'      'processing'     'processing'     'successful-ok'                                         No effect on the job.      'processing-     'processing-     'successful-ok'       stopped'         stopped'         No effect on the job.      'completed'      'completed'      'client-error-not-possible'      'canceled'       'canceled'       'client-error-not-possible'      'aborted'        'aborted'        'client-error-not-possible'   Rule 1:  If there are other reasons to keep the job in the 'pending-   held' state, such as 'resources-are-not-ready', the job remains in   the 'pending-held' state.  Thus the 'pending-held' state is not just   for jobs that have the 'job-hold-until' applied to them, but are for   any reason to keep the job from being a candidate for scheduling and   processing, such as 'resources-are-not-ready'.  See the "job-hold-   until" attribute (section 4.2.2).   Access Rights: The authenticated user (seesection 8.3) performing   this operation must either be the job owner or an operator or   administrator of the Printer object (see Sections1 and8.5).   Otherwise, the IPP object MUST reject the operation and return:   'client-error-forbidden', 'client-error-not-authenticated', or   'client-error-not-authorized' as appropriate.Hastings, et al.            Standards Track                    [Page 74]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The Release-Job Request and Release-Job Response have the same   attribute groups and attributes as the Cancel-Job operation (seesection 3.3.3.1 and 3.3.3.2).3.3.7 Restart-Job Operation   This OPTIONAL operation allows a client to restart a job that is   retained in the queue after processing has completed (seesection4.3.7.2).   The job is moved to the 'pending' or 'pending-held' job state and   restarts at the beginning on the same IPP Printer object with the   same attribute values.  If any of the documents in the job were   passed by reference (Print-URI or Send-URI), the Printer MUST re-   fetch the data, since the semantics of Restart-Job are to repeat all   Job processing.  The Job Description attributes that accumulate job   progress, such as "job-impressions-completed", "job-media-sheets-   completed", and "job-k-octets-processed", MUST be reset to 0 so that   they give an accurate record of the job from its restart point.  The   job object MUST continue to use the same "job-uri" and "job-id"   attribute values.   Note:  If in the future an operation is needed that does not reset   the job progress attributes, then a new operation will be defined   which makes a copy of the job, assigns a new "job-uri" and "job-id"   to the copy and resets the job progress attributes in the new copy   only.   The IPP object MUST accept or reject the request based on the job's   current state, transition the job to the indicated new state as   follows:Hastings, et al.            Standards Track                    [Page 75]

RFC 2911              IPP/1.1: Model and Semantics        September 2000        Current "job-   New "job-state"    IPP object's response status           state"                                code and action:      'pending'        'pending'        'client-error-not-possible'      'pending-held'   'pending-held'   'client-error-not-possible'      'processing'     'processing'     'client-error-not-possible'      'processing-     'processing-     'client-error-not-possible'      stopped'         stopped'      'completed'      'pending' or     'successful-ok' - job is started                        'pending-held'   over.      'completed'      'completed'      'client-error-not-possible' -                                         see Rule 1      'canceled'       'pending' or     'successful-ok' - job is started                        'pending-held'   over.      'canceled'       'canceled'       'client-error-not-possible' -                                         see Rule 1      'aborted'        'pending' or     'successful-ok' - job is started                        'pending-held'   over.      'aborted'        'aborted'        'client-error-not-possible' -                                         see Rule 1   Rule 1:  If the Job Retention Period has expired for the job in this   state, then the IPP object rejects the operation.  Seesection4.3.7.2.   Note:  In order to prevent a user from inadvertently restarting a job   in the middle, the Restart-Job request is rejected when the job is in   the 'processing' or 'processing-stopped' states.  If in the future an   operation is needed to hold or restart jobs while in these states, it   will be added as an additional operation, rather than overloading the   Restart-Job operation, so that it is clear that the user intended   that the current job not be completed.   Access Rights: The authenticated user (seesection 8.3) performing   this operation must either be the job owner or an operator or   administrator of the Printer object (see Sections1 and8.5).   Otherwise, the IPP object MUST reject the operation and return:   'client-error-forbidden', 'client-error-not-authenticated', or   'client-error-not-authorized' as appropriate.3.3.7.1 Restart-Job Request   The groups and attributes are the same as for a Cancel-Job request   (seesection 3.3.3.1), with the addition of the following Group 1   Operation attribute:Hastings, et al.            Standards Track                    [Page 76]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      "job-hold-until" (type3 keyword | name(MAX)):         The client OPTIONALLY supplies this attribute.  The IPP object         MUST support this Operation attribute in a Restart-Job request,         if it supports the "job-hold-until" Job Template attribute in         create operations.  Seesection 4.2.2.  Otherwise, the IPP         object NEED NOT support the "job-hold-until" Operation         attribute in a Restart-Job request.         If supplied and supported as specified in the Printer's "job-         hold-until-supported" attribute, the IPP object copies the         supplied Operation attribute to the Job object, replacing the         job's previous "job-hold-until" attribute, if present, and         makes the job a candidate for scheduling during the supplied         named time period.  Seesection 4.2.2.         If supplied, but the value is not supported, the IPP object         accepts the request, returns the unsupported attribute or value         in the Unsupported Attributes Group according tosection 3.1.7,         returns the 'successful-ok-ignored-or-substituted-attributes'         status code, and holds the job indefinitely until a client         performs a subsequent Release-Job operation.         If supplied, but the "job-hold-until" Operation attribute         itself is not supported, the IPP object accepts the request,         returns the unsupported attribute with the out-of-band         'unsupported' value in the Unsupported Attributes Group         according tosection 3.1.7, returns the 'successful-ok-         ignored-or-substituted-attributes' status code, and restarts         the job, i.e., ignores the "job-hold-until" attribute.         If the client (1) supplies a value that specifies a time period         that has already started or the 'no-hold' value (meaning don't         hold the job) and (2) the IPP object supports the "job-hold-         until" operation attribute and there are no other reasons to         hold the job, the IPP object makes the job a candidate for         processing immediately (seeSection 4.2.2).         If the client does not supply a "job-hold-until" operation         attribute in the request, the IPP object removes the "job-         hold-until" attribute, if present, from the job.  If there are         no other reasons to hold the job, the Restart-Job operation         makes the job a candidate for processing immediately (seeSection 4.2.2).Hastings, et al.            Standards Track                    [Page 77]

RFC 2911              IPP/1.1: Model and Semantics        September 20003.3.7.2 Restart-Job Response   The groups and attributes are the same as for a Cancel-Job response   (seesection 3.3.3.2).   Note:  In the future an OPTIONAL Modify-Job or Set-Job-Attributes   operation may be specified that allows the client to modify other   attributes before releasing the restarted job.4. Object Attributes   This section describes the attributes with their corresponding   attribute syntaxes and values that are part of the IPP model.  The   sections below show the objects and their associated attributes which   are included within the scope of this protocol.  Many of these   attributes are derived from other relevant documents:      - Document Printing Application (DPA) [ISO10175]      -RFC 1759 Printer MIB [RFC1759]   Each attribute is uniquely identified in this document using a   "keyword" (seesection 12.2.1) which is the name of the attribute.   The keyword is included in the section header describing that   attribute.   Note:  Not only are keywords used to identify attributes, but one of   the attribute syntaxes described below is "keyword" so that some   attributes have keyword values.  Therefore, these attributes are   defined as having an attribute syntax that is a set of keywords.4.1 Attribute Syntaxes   This section defines the basic attribute syntax types that all   clients and IPP objects MUST be able to accept in responses and   accept in requests, respectively.  Each attribute description in   sections3 and4 includes the name of attribute syntax(es) in the   heading (in parentheses).  A conforming implementation of an   attribute MUST include the semantics of the attribute syntax(es) so   identified.Section 6.3 describes how the protocol can be extended   with new attribute syntaxes.   The attribute syntaxes are specified in the following sub-sections,   where the sub-section heading is the keyword name of the attribute   syntax inside the single quotes.  In operation requests and responses   each attribute value MUST be represented as one of the attribute   syntaxes specified in the sub-section heading for the attribute.  In   addition, the value of an attribute in a response (but not in aHastings, et al.            Standards Track                    [Page 78]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   request) MAY be one of the "out-of-band" values whose special   encoding rules are defined in the "Encoding and Transport" document   [RFC2910].   Standard "out-of-band" values are:      'unknown': The attribute is supported by the IPP object, but the         value is unknown to the IPP object for some reason.      'unsupported': The attribute is unsupported by the IPP object.         This value MUST be returned only as the value of an attribute         in the Unsupported Attributes Group.      'no-value': The attribute is supported by the Printer object, but         the administrator has not yet configured a value.   All attributes in a request MUST have one or more values as defined   in Sections4.2 to4.4.  Thus clients MUST NOT supply attributes with   "out-of-band" values for operations defined in this document.  All   attributes in a response MUST have one or more values as defined in   Sections4.2 to4.4 or a single "out-of-band" value.   Most attributes are defined to have a single attribute syntax.   However, a few attributes (e.g., "job-sheet", "media", "job-hold-   until") are defined to have several attribute syntaxes, depending on   the value.  These multiple attribute syntaxes are separated by the   "|" character in the sub-section heading to indicate the choice.   Since each value MUST be tagged as to its attribute syntax in the   protocol, a single-valued attribute instance may have any one of its   attribute syntaxes and a multi-valued attribute instance may have a   mixture of its defined attribute syntaxes.4.1.1 'text'   A text attribute is an attribute whose value is a sequence of zero or   more characters encoded in a maximum of 1023 ('MAX') octets.  MAX is   the maximum length for each value of any text attribute.  However, if   an attribute will always contain values whose maximum length is much   less than MAX, the definition of that attribute will include a   qualifier that defines the maximum length for values of that   attribute.  For example:  the "printer-location" attribute is   specified as "printer-location (text(127))".  In this case, text   values for "printer-location" MUST NOT exceed 127 octets; if supplied   with a longer text string via some external interface (other than the   protocol), implementations are free to truncate to this shorter   length limitation.   In this document, all text attributes are defined using the 'text'   syntax.  However, 'text' is used only for brevity; the formal   interpretation of 'text' is: 'textWithoutLanguage |   textWithLanguage'.  That is, for any attribute defined in this   document using the 'text' attribute syntax, all IPP objects andHastings, et al.            Standards Track                    [Page 79]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   clients MUST support both the 'textWithoutLanguage' and   'textWithLanguage' attribute syntaxes.  However, in actual usage and   protocol execution, objects and clients accept and return only one of   the two syntax per attribute.  The syntax 'text' never appears "on-   the-wire".   Both 'textWithoutLanguage' and 'textWithLanguage' are needed to   support the real world needs of interoperability between sites and   systems that use different natural languages as the basis for human   communication.  Generally, one natural language applies to all text   attributes in a given request or response. The language is indicated   by the "attributes-natural-language" operation attribute defined insection 3.1.4 or "attributes-natural-language" job attribute defined   insection 4.3.20, and there is no need to identify the natural   language for each text string on a value-by-value basis.  In these   cases, the attribute syntax 'textWithoutLanguage' is used for text   attributes.  In other cases, the client needs to supply or the   Printer object needs to return a text value in a natural language   that is different from the rest of the text values in the request or   response.  In these cases, the client or Printer object uses the   attribute syntax 'textWithLanguage' for text attributes (this is the   Natural Language Override mechanism described insection 3.1.4).   The 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes   are described in more detail in the following sections.4.1.1.1 'textWithoutLanguage'   The 'textWithoutLanguage' syntax indicates a value that is sequence   of zero or more characters encoded in a maximum of 1023 (MAX) octets.   Text strings are encoded using the rules of some charset.  The   Printer object MUST support the UTF-8 charset [RFC2279] and MAY   support additional charsets to represent 'text' values, provided that   the charsets are registered with IANA [IANA-CS].  SeeSection 4.1.7   for the definition of the 'charset' attribute syntax, including   restricted semantics and examples of charsets.4.1.1.2 'textWithLanguage'   The 'textWithLanguage' attribute syntax is a compound attribute   syntax consisting of two parts: a 'textWithoutLanguage' part encoded   in a maximum of 1023 (MAX) octets plus an additional   'naturalLanguage' (seesection 4.1.8) part that overrides the natural   language in force.  The 'naturalLanguage' part explicitly identifies   the natural language that applies to the text part of that value and   that value alone.  For any give text attribute, the   'textWithoutLanguage' part is limited to the maximum length defined   for that 'text' attribute, and the 'naturalLanguage' part is alwaysHastings, et al.            Standards Track                    [Page 80]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   limited to 63 (additional) octets.  Using the 'textWithLanguage'   attribute syntax rather than the normal 'textWithoutLanguage' syntax   is the so-called Natural Language Override mechanism and MUST be   supported by all IPP objects and clients.   If the attribute is multi-valued (1setOf text), then the   'textWithLanguage' attribute syntax MUST be used to explicitly   specify each attribute value whose natural language needs to be   overridden.  Other values in a multi-valued 'text' attribute in a   request or a response revert to the natural language of the operation   attribute.   In a create request, the Printer object MUST accept and store with   the Job object any natural language in the "attributes-natural-   language" operation attribute, whether the Printer object supports   that natural language or not.  Furthermore, the Printer object MUST   accept and store any 'textWithLanguage' attribute value, whether the   Printer object supports that natural language or not.  These   requirements are independent of the value of the "ipp-attribute-   fidelity" operation attribute that the client MAY supply.   Example:  If the client supplies the "attributes-natural-language"   operation attribute with the value: 'en' indicating English, but the   value of the "job-name" attribute is in French, the client MUST use   the 'textWithLanguage' attribute syntax with the following two   values:      'fr': Natural Language Override indicating French      'Rapport Mensuel': the job name in French   See the "Encoding and Transport" document[RFC2910] section 3.9 for   the encoding of the two parts andAppendix A for a detailed example   of the 'textWithLanguage' attribute syntax.4.1.2 'name'   This syntax type is used for user-friendly strings, such as a Printer   name, that, for humans, are more meaningful than identifiers.  Names   are never translated from one natural language to another.  The   'name' attribute syntax is essentially the same as 'text', including   the REQUIRED support of UTF-8 except that the sequence of characters   is limited so that its encoded form MUST NOT exceed 255 (MAX) octets.   Also like 'text', 'name' is really an abbreviated notation for either   'nameWithoutLanguage' or 'nameWithLanguage'.  That is, all IPP   objects and clients MUST support both the 'nameWithoutLanguage' and   'nameWithLanguage' attribute syntaxes.  However, in actual usage andHastings, et al.            Standards Track                    [Page 81]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   protocol execution, objects and clients accept and return only one of   the two syntax per attribute.  The syntax 'name' never appears "on-   the-wire".   Only the 'text' and 'name' attribute syntaxes permit the Natural   Language Override mechanism.   Some attributes are defined as 'type3 keyword | name'.  These   attributes support values that are either type3 keywords or names.   This dual-syntax mechanism enables a site administrator to extend   these attributes to legally include values that are locally defined   by the site administrator.  Such names are not registered with IANA.4.1.2.1 'nameWithoutLanguage'   The 'nameWithoutLanguage' syntax indicates a value that is sequence   of zero or more characters encoded in a maximum of 255 (MAX) octets.4.1.2.2 'nameWithLanguage'   The 'nameWithLanguage' attribute syntax is a compound attribute   syntax consisting of two parts: a 'nameWithoutLanguage' part encoded   in a maximum of 1023 (MAX) octets plus an additional   'naturalLanguage' (seesection 4.1.8) part that overrides the natural   language in force.  The 'naturalLanguage' part explicitly identifies   the natural language that applies to that name value and that name   value alone.  For any give text attribute, the 'textWithoutLanguage'   part is limited to the maximum length defined for that 'text'   attribute, and the 'naturalLanguage' part is always limited to 63   (additional) octets.  Using the 'textWithLanguage' attribute syntax   rather than the normal 'textWithoutLanguage' syntax is the so-called   Natural Language Override mechanism and MUST be supported by all IPP   objects and clients.   The 'nameWithLanguage' attribute syntax behaves the same as the   'textWithLanguage' syntax.  Using the 'textWithLanguage' attribute   syntax rather than the normal 'textWithoutLanguage' syntax is the   so-called Natural Language Override mechanism and MUST be supported   by all IPP objects and clients.  If a name is in a language that is   different than the rest of the object or operation, then this   'nameWithLanguage' syntax is used rather than the generic   'nameWithoutLanguage' syntax.   If the attribute is multi-valued (1setOf text), then the   'nameWithLanguage' attribute syntax MUST be used to explicitly   specify each attribute value whose natural language needs to be   overridden.Hastings, et al.            Standards Track                    [Page 82]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Other values in a multi-valued 'name' attribute in a request or a   response revert to the natural language of the operation attribute.   In a create request, the Printer object MUST accept and store with   the Job object any natural language in the "attributes-natural-   language" operation attribute, whether the Printer object supports   that natural language or not.  Furthermore, the Printer object MUST   accept and store any 'nameWithLanguage' attribute value, whether the   Printer object supports that natural language or not.  These   requirements are independent of the value of the "ipp-attribute-   fidelity" operation attribute that the client MAY supply.   Example:  If the client supplies the "attributes-natural-language"   operation attribute with the value:  'en' indicating English, but the   "printer-name" attribute is in German, the client MUST use the   'nameWithLanguage' attribute syntax as follows:      'de':  Natural Language Override indicating German      'Farbdrucker':  the Printer name in German   See the "Encoding and Transport" document[RFC2910] section 3.9 for   the encoding of the two parts andAppendix A for a detailed example   of the 'nameWithLanguage' attribute syntax.4.1.2.3 Matching 'name' attribute values   For purposes of matching two 'name' attribute values for equality,   such as in job validation (where a client-supplied value for   attribute "xxx" is checked to see if the value is among the values of   the Printer object's corresponding "xxx-supported" attribute), the   following match rules apply:      1. 'keyword' values never match 'name' values.      2. 'name' (nameWithoutLanguage and nameWithLanguage) values match         if (1) the name parts match and (2) the Associated Natural-         Language parts (seesection 3.1.4.1) match.  The matching rules         are:         a. the name parts match if the two names are identical            character by character, except it is RECOMMENDED that case            be ignored.  For example: 'Ajax-letter-head-white' MUST            match 'Ajax-letter-head-white' and SHOULD match 'ajax-            letter-head-white' and 'AJAX-LETTER-HEAD-WHITE'.Hastings, et al.            Standards Track                    [Page 83]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         b. the Associated Natural-Language parts match if the shorter            of the two meets the syntactic requirements ofRFC 1766            [RFC1766] and matches byte for byte with the longer.  For            example, 'en' matches 'en', 'en-us' and 'en-gb', but matches            neither 'fr' nor 'e'.4.1.3 'keyword'   The 'keyword' attribute syntax is a sequence of characters, length: 1   to 255, containing only the US-ASCII [ASCII] encoded values for   lowercase letters ("a" - "z"), digits ("0" - "9"), hyphen ("-"), dot   ("."), and underscore ("_").  The first character MUST be a lowercase   letter.  Furthermore, keywords MUST be in U.S. English.   This syntax type is used for enumerating semantic identifiers of   entities in the abstract protocol, i.e., entities identified in this   document.  Keywords are used as attribute names or values of   attributes.  Unlike 'text' and 'name' attribute values, 'keyword'   values MUST NOT use the Natural Language Override mechanism, since   they MUST always be US-ASCII and U.S. English.   Keywords are for use in the protocol.  A user interface will likely   provide a mapping between protocol keywords and displayable user-   friendly words and phrases which are localized to the natural   language of the user.  While the keywords specified in this document   MAY be displayed to users whose natural language is U.S. English,   they MAY be mapped to other U.S. English words for U.S. English   users, since the user interface is outside the scope of this   document.   In the definition for each attribute of this syntax type, the full   set of defined keyword values for that attribute are listed.   When a keyword is used to represent an attribute (its name), it MUST   be unique within the full scope of all IPP objects and attributes.   When a keyword is used to represent a value of an attribute, it MUST   be unique just within the scope of that attribute.  That is, the same   keyword MUST NOT be used for two different values within the same   attribute to mean two different semantic ideas.  However, the same   keyword MAY be used across two or more attributes, representing   different semantic ideas for each attribute.Section 6.1 describes   how the protocol can be extended with new keyword values.  Examples   of attribute name keywords:      "job-name"      "attributes-charset"Hastings, et al.            Standards Track                    [Page 84]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Note:  This document uses "type1", "type2", and "type3" prefixes to   the "keyword" basic syntax to indicate different levels of review for   extensions (seesection 6.1).4.1.4 'enum'   The 'enum' attribute syntax is an enumerated integer value that is in   the range from 1 to 2**31 - 1 (MAX).   Each value has an associated   'keyword' name.  In the definition for each attribute of this syntax   type, the full set of possible values for that attribute are listed.   This syntax type is used for attributes for which there are enum   values assigned by other standards, such as SNMP MIBs.  A number of   attribute enum values in this document are also used for   corresponding attributes in other standards [RFC1759].  This syntax   type is not used for attributes to which the administrator may assign   values.Section 6.1 describes how the protocol can be extended with   new enum values.   Enum values are for use in the protocol.  A user interface will   provide a mapping between protocol enum values and displayable user-   friendly words and phrases which are localized to the natural   language of the user.  While the enum symbols specified in this   document MAY be displayed to users whose natural language is U.S.   English, they MAY be mapped to other U.S. English words for U.S.   English users, since the user interface is outside the scope of this   document.   Note: SNMP MIBs use '2' for 'unknown' which corresponds to the IPP   "out-of-band" value 'unknown'.  See the description of the "out-of-   band" values at the beginning ofSection 4.1.  Therefore, attributes   of type 'enum' start at '3'.   Note:  This document uses "type1", "type2", and "type3" prefixes to   the "enum" basic syntax to indicate different levels of review for   extensions (seesection 6.1).4.1.5 'uri'   The 'uri' attribute syntax is any valid Uniform Resource Identifier   or URI [RFC2396].  Most often, URIs are simply Uniform Resource   Locators or URLs.  The maximum length of URIs used as values of IPP   attributes is 1023 octets.  Although most other IPP attribute syntax   types allow for only lower-cased values, this attribute syntax type   conforms to the case-sensitive and case-insensitive rules specified   in [RFC2396].  See also [IPP-IIG] for a discussion of case in URIs.Hastings, et al.            Standards Track                    [Page 85]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.1.6 'uriScheme'   The 'uriScheme' attribute syntax is a sequence of characters   representing a URI scheme according toRFC 2396 [RFC2396].  ThoughRFC 2396 requires that the values be case-insensitive, IPP requires   all lower case values in IPP attributes to simplify comparing by IPP   clients and Printer objects.   Standard values for this syntax type are the following keywords:      'ipp':  for IPP schemed URIs (e.g., "ipp:...")      'http':  for HTTP schemed URIs (e.g., "http:...")      'https':  for use with HTTPS schemed URIs (e.g., "https:...") (not         on IETF standards track)      'ftp': for FTP schemed URIs (e.g., "ftp:...")      'mailto': for SMTP schemed URIs (e.g., "mailto:...")      'file': for file schemed URIs (e.g., "file:...")   A Printer object MAY support any URI 'scheme' that has been   registered with IANA [IANA-MT]. The maximum length of URI 'scheme'   values used to represent IPP attribute values is 63 octets.4.1.7 'charset'   The 'charset' attribute syntax is a standard identifier for a   charset.  A charset is a coded character set and encoding scheme.   Charsets are used for labeling certain document contents and 'text'   and 'name' attribute values.  The syntax and semantics of this   attribute syntax are specified inRFC 2046 [RFC2046] and contained in   the IANA character-set Registry [IANA-CS] according to the IANA   procedures [RFC2278].  ThoughRFC 2046 requires that the values be   case-insensitive US-ASCII [ASCII], IPP requires all lower case values   in IPP attributes to simplify comparing by IPP clients and Printer   objects.  When a character-set in the IANA registry has more than one   name (alias), the name labeled as "(preferred MIME name)", if   present, MUST be used.   The maximum length of 'charset' values used to represent IPP   attribute values is 63 octets.   Some examples are:      'utf-8':  ISO 10646 Universal Multiple-Octet Coded Character Set         (UCS) represented as the UTF-8 [RFC2279] transfer encoding         scheme in which US-ASCII is a subset charset.      'us-ascii':  7-bit American Standard Code for Information         Interchange (ASCII), ANSI X3.4-1986 [ASCII].  That standardHastings, et al.            Standards Track                    [Page 86]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         defines US-ASCII, butRFC 2045 [RFC2045] eliminates most of the         control characters from conformant usage in MIME and IPP.      'iso-8859-1':  8-bit One-Byte Coded Character Set, Latin Alphabet         Nr 1 [ISO8859-1].  That standard defines a coded character set         that is used by Latin languages in the Western Hemisphere and         Western Europe.  US-ASCII is a subset charset.   Some attribute descriptions MAY place additional requirements on   charset values that may be used, such as REQUIRED values that MUST be   supported or additional restrictions, such as requiring that the   charset have US- ASCII as a subset charset.4.1.8 'naturalLanguage'   The 'naturalLanguage' attribute syntax is a standard identifier for a   natural language and optionally a country.  The values for this   syntax type are defined byRFC 1766 [RFC1766].  ThoughRFC 1766   requires that the values be case-insensitive US-ASCII [ASCII], IPP   requires all lower case to simplify comparing by IPP clients and   Printer objects.  Examples include:      'en':  for English      'en-us': for US English      'fr': for French      'de':  for German   The maximum length of 'naturalLanguage' values used to represent IPP   attribute values is 63 octets.4.1.9 'mimeMediaType'   The 'mimeMediaType' attribute syntax is the Internet Media Type   (sometimes called MIME type) as defined byRFC 2046 [RFC2046] and   registered according to the procedures ofRFC 2048 [RFC2048] for   identifying a document format.  The value MAY include a charset, or   other, parameter, depending on the specification of the Media Type in   the IANA Registry [IANA-MT].  Although most other IPP syntax types   allow for only lower-cased values, this syntax type allows for   mixed-case values which are case-insensitive.   Examples are:      'text/html': An HTML document      'text/plain': A plain text document in US-ASCII (RFC 2046         indicates that in the absence of the charset parameter MUST         mean US-ASCII rather than simply unspecified) [RFC2046].      'text/plain; charset=US-ASCII':  A plain text document in US-ASCII         [52, 56].Hastings, et al.            Standards Track                    [Page 87]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      'text/plain; charset=ISO-8859-1':  A plain text document in ISO         8859-1 (Latin 1) [ISO8859-1].      'text/plain; charset=utf-8':  A plain text document in ISO 10646         represented as UTF-8 [RFC2279]      'application/postscript':  A PostScript document [RFC2046]      'application/vnd.hp-PCL':  A PCL document [IANA-MT] (charset         escape sequence embedded in the document data)      'application/pdf':  Portable Document Format - see IANA MIME Media         Type registry      'application/octet-stream': Auto-sense - seesection 4.1.9.1   The maximum length of a 'mimeMediaType' value to represent IPP   attribute values is 255 octets.4.1.9.1 Application/octet-stream -- Auto-Sensing the document format   One special type is 'application/octet-stream'.  If the Printer   object supports this value, the Printer object MUST be capable of   auto-sensing the format of the document data using an   implementation-dependent method that examines some number of octets   of the document data, either as part of the create operation and/or   at document processing time.  During auto-sensing, a Printer may   determine that the document-data has a format that the Printer   doesn't recognize.  If the Printer determines this problem before   returning an operation response, it rejects the request and returns   the 'client-error-document-format-not-supported' status code.  If the   Printer determines this problem after accepting the request and   returning an operation response with one of the successful status   codes, the Printer adds the 'unsupported-document-format' value to   the job's "job-state-reasons" attribute.   If the Printer object's default value attribute "document-format-   default" is set to 'application/octet-stream', the Printer object not   only supports auto-sensing of the document format, but will depend on   the result of applying its auto-sensing when the client does not   supply the "document-format" attribute.  If the client supplies a   document format value, the Printer MUST rely on the supplied   attribute, rather than trust its auto-sensing algorithm.  To   summarize:      1. If the client does not supply a document format value, the         Printer MUST rely on its default value setting (which may be         'application/octet-stream' indicating an auto-sensing         mechanism).      2. If the client supplies a value other than 'application/octet-         stream', the client is supplying valid information about the         format of the document data and the Printer object MUST trust         the client supplied value more than the outcome of applying anHastings, et al.            Standards Track                    [Page 88]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         automatic format detection mechanism.  For example, the client         may be requesting the printing of a PostScript file as a         'text/plain' document.  The Printer object MUST print a text         representation of the PostScript commands rather than interpret         the stream of PostScript commands and print the result.      3. If the client supplies a value of 'application/octet-stream',         the client is indicating that the Printer object MUST use its         auto-sensing mechanism on the client supplied document data         whether auto-sensing is the Printer object's default or not.   Note:  Since the auto-sensing algorithm is probabilistic, if the   client requests both auto-sensing ("document-format" set to   'application/octet-stream') and true fidelity ("ipp-attribute-   fidelity" set to 'true'), the Printer object might not be able to   guarantee exactly what the end user intended (the auto-sensing   algorithm might mistake one document format for another), but it is   able to guarantee that its auto-sensing mechanism be used.   When a Printer performs auto-sensing of a document in a submitted   job, it is RECOMMENDED that the Printer indicate to the user that   such auto-sensing has occurred and which document-format was auto-   sensed by printing that information on the job's job-start-sheet.4.1.10 'octetString'   The 'octetString' attribute syntax is a sequence of octets encoded in   a maximum of 1023 octets which is indicated in sub-section headers   using the notation: octetString(MAX).  This syntax type is used for   opaque data.4.1.11 'boolean'   The 'boolean' attribute syntax has only two values:  'true' and   'false'.4.1.12 'integer'   The 'integer' attribute syntax is an integer value that is in the   range from -2**31 (MIN) to 2**31 - 1 (MAX).  Each individual   attribute may specify the range constraint explicitly in sub-section   headers if the range is different from the full range of possible   integer values.  For example:  job-priority (integer(1:100)) for the   "job-priority" attribute.  However, the enforcement of that   additional constraint is up to the IPP objects, not the protocol.Hastings, et al.            Standards Track                    [Page 89]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.1.13 'rangeOfInteger'   The 'rangeOfInteger' attribute syntax is an ordered pair of integers   that defines an inclusive range of integer values.  The first integer   specifies the lower bound and the second specifies the upper bound.   If a range constraint is specified in the header description for an   attribute in this document whose attribute syntax is 'rangeOfInteger'   (i.e., 'X:Y' indicating X as a minimum value and Y as a maximum   value), then the constraint applies to both integers.4.1.14 'dateTime'   The 'dateTime' attribute syntax is a standard, fixed length, 11 octet   representation of the "DateAndTime" syntax as defined inRFC 2579   [RFC2579].RFC 2579 also identifies an 8 octet representation of a   "DateAndTime" value, but IPP objects MUST use the 11 octet   representation.  A user interface will provide a mapping between   protocol dateTime values and displayable user-friendly words or   presentation values and phrases which are localized to the natural   language and date format of the user, including time zone.4.1.15 'resolution'   The 'resolution' attribute syntax specifies a two-dimensional   resolution in the indicated units.  It consists of 3 values: a cross   feed direction resolution (positive integer value), a feed direction   resolution (positive integer value), and a units value.  The   semantics of these three components are taken from the Printer MIB   [RFC1759] suggested values.  That is, the cross feed direction   component resolution component is the same as the   prtMarkerAddressabilityXFeedDir object in the Printer MIB, the feed   direction component resolution component is the same as the   prtMarkerAddressabilityFeedDir in the Printer MIB, and the units   component is the same as the prtMarkerAddressabilityUnit object in   the Printer MIB (namely, '3' indicates dots per inch and '4'   indicates dots per centimeter).  All three values MUST be present   even if the first two values are the same.  Example:  '300', '600',   '3' indicates a 300 dpi cross-feed direction resolution, a 600 dpi   feed direction resolution, since a '3' indicates dots per inch (dpi).4.1.16 '1setOfX'   The '1setOf  X' attribute syntax is 1 or more values of attribute   syntax type X.  This syntax type is used for multi-valued attributes.   The syntax type is called '1setOf' rather than just 'setOf' as a   reminder that the set of values MUST NOT be empty (i.e., a set ofHastings, et al.            Standards Track                    [Page 90]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   size 0).  Sets are normally unordered.  However each attribute   description of this type may specify that the values MUST be in a   certain order for that attribute.4.2 Job Template Attributes   Job Template attributes describe job processing behavior.  Support   for Job Template attributes by a Printer object is OPTIONAL (seesection 12.2.3 for a description of support for OPTIONAL attributes).   Also, clients OPTIONALLY supply Job Template attributes in create   requests.   Job Template attributes conform to the following rules.  For each Job   Template attribute called "xxx":      1. If the Printer object supports "xxx" then it MUST support both         a "xxx-default" attribute (unless there is a "No" in the table         below) and a "xxx-supported" attribute.  If the Printer object         doesn't support "xxx", then it MUST support neither an "xxx-         default" attribute nor an "xxx-supported" attribute, and it         MUST treat an attribute "xxx" supplied by a client as         unsupported.  An attribute "xxx" may be supported for some         document formats and not supported for other document formats.         For example, it is expected that a Printer object would only         support "orientation-requested" for some document formats (such         as 'text/plain' or 'text/html') but not others (such as         'application/postscript').      2. "xxx" is OPTIONALLY supplied by the client in a create request.         If "xxx" is supplied, the client is indicating a desired job         processing behavior for this Job.  When "xxx" is not supplied,         the client is indicating that the Printer object apply its         default job processing behavior at job processing time if the         document content does not contain an embedded instruction         indicating an xxx-related behavior.         Since an administrator MAY change the default value attribute         after a Job object has been submitted but before it has been         processed, the default value used by the Printer object at job         processing time may be different that the default value in         effect at job submission time.      3. The "xxx-supported" attribute is a Printer object attribute         that describes which job processing behaviors are supported by         that Printer object.  A client can query the Printer object to         find out what xxx-related behaviors are supported by inspecting         the returned values of the "xxx-supported" attribute.Hastings, et al.            Standards Track                    [Page 91]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         Note: The "xxx" in each "xxx-supported" attribute name is         singular, even though an "xxx-supported" attribute usually has         more than one value, such as "job-sheet-supported", unless the         "xxx" Job Template attribute is plural, such as "finishings" or         "sides".  In such cases the "xxx-supported" attribute names         are: "finishings- supported" and "sides-supported".      4. The "xxx-default" default value attribute describes what will         be done at job processing time when no other job processing         information is supplied by the client (either explicitly as an         IPP attribute in the create request or implicitly as an         embedded instruction within the document data).   If an application wishes to present an end user with a list of   supported values from which to choose, the application SHOULD query   the Printer object for its supported value attributes.  The   application SHOULD also query the default value attributes.  If the   application then limits selectable values to only those value that   are supported, the application can guarantee that the values supplied   by the client in the create request all fall within the set of   supported values at the Printer.  When querying the Printer, the   client MAY enumerate each attribute by name in the Get-Printer-   Attributes Request, or the client MAY just name the "job-template"   group in order to get the complete set of supported attributes (both   supported and default attributes).   The "finishings" attribute is an example of a Job Template attribute.   It can take on a set of values such as 'staple', 'punch', and/or   'cover'.  A client can query the Printer object for the "finishings-   supported" attribute and the "finishings-default" attribute.  The   supported attribute contains a set of supported values.  The default   value attribute contains the finishing value(s) that will be used for   a new Job if the client does not supply a "finishings" attribute in   the create request and the document data does not contain any   corresponding finishing instructions.  If the client does supply the   "finishings" attribute in the create request, the IPP object   validates the value or values to make sure that they are a subset of   the supported values identified in the Printer object's "finishings-   supported" attribute.  Seesection 3.1.7.   The table below summarizes the names and relationships for all Job   Template attributes. The first column of the table (labeled "Job   Attribute") shows the name and syntax for each Job Template attribute   in the Job object. These are the attributes that can optionally be   supplied by the client in a create request.   The last two columns   (labeled "Printer: Default Value Attribute" and "Printer: Supported   Values Attribute") show the name and syntax for each Job Template   attribute in the Printer object (the default value attribute and theHastings, et al.            Standards Track                    [Page 92]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   supported values attribute).  A "No" in the table means the Printer   MUST NOT support the attribute (that is, the attribute is simply not   applicable).  For brevity in the table, the 'text' and 'name' entries   do not show the maximum length for each attribute.     +===================+======================+======================+     | Job Attribute     |Printer: Default Value|  Printer: Supported  |     |                   |   Attribute          |   Values Attribute   |     +===================+======================+======================+     | job-priority      | job-priority-default |job-priority-supported|     | (integer 1:100)   | (integer 1:100)      |(integer 1:100)       |     +-------------------+----------------------+----------------------+     | job-hold-until    | job-hold-until-      |job-hold-until-       |     | (type3 keyword |  |  default             | supported            |     |    name)          |  (type3 keyword |    |(1setOf (             |     |                   |    name)             |type3 keyword | name))|     +-------------------+----------------------+----------------------+     | job-sheets        | job-sheets-default   |job-sheets-supported  |     | (type3 keyword |  | (type3 keyword |     |(1setOf (             |     |    name)          |    name)             |type3 keyword | name))|     +-------------------+----------------------+----------------------+     |multiple-document- |multiple-document-    |multiple-document-    |     | handling          | handling-default     |handling-supported    |     | (type2 keyword)   | (type2 keyword)      |(1setOf type2 keyword)|     +-------------------+----------------------+----------------------+     | copies            | copies-default       | copies-supported     |     | (integer (1:MAX)) | (integer (1:MAX))    | (rangeOfInteger      |     |                   |                      |       (1:MAX))       |     +-------------------+----------------------+----------------------+     | finishings        | finishings-default   | finishings-supported |     |(1setOf type2 enum)|(1setOf type2 enum)   |(1setOf type2 enum)   |     +-------------------+----------------------+----------------------+     | page-ranges       | No                   | page-ranges-         |     | (1setOf           |                      | supported (boolean)  |     |   rangeOfInteger  |                      |                      |     |        (1:MAX))   |                      |                      |     +-------------------+----------------------+----------------------+     | sides             | sides-default        | sides-supported      |     | (type2 keyword)   | (type2 keyword)      |(1setOf type2 keyword)|     +-------------------+----------------------+----------------------+     | number-up         | number-up-default    | number-up-supported  |     | (integer (1:MAX)) | (integer (1:MAX))    |(1setOf (integer      |     |                   |                      | (1:MAX) |            |     |                   |                      |  rangeOfInteger      |     |                   |                      |   (1:MAX)))          |Hastings, et al.            Standards Track                    [Page 93]

RFC 2911              IPP/1.1: Model and Semantics        September 2000     +-------------------+----------------------+----------------------+     | orientation-      |orientation-requested-|orientation-requested-|     |  requested        |  default             |  supported           |     |   (type2 enum)    |  (type2 enum)        |  (1setOf type2 enum) |     +-------------------+----------------------+----------------------+     | media             | media-default        | media-supported      |     | (type3 keyword |  | (type3 keyword |     |(1setOf (             |     |    name)          |    name)             |type3 keyword | name))|     |                   |                      |                      |     |                   |                      | media-ready          |     |                   |                      |(1setOf (             |     |                   |                      |type3 keyword | name))|     +-------------------+----------------------+----------------------+     | printer-resolution| printer-resolution-  | printer-resolution-  |     | (resolution)      |  default             | supported            |     |                   | (resolution)         |(1setOf resolution)   |     +-------------------+----------------------+----------------------+     | print-quality     | print-quality-default| print-quality-       |     | (type2 enum)      | (type2 enum)         | supported            |     |                   |                      |(1setOf type2 enum)   |     +-------------------+----------------------+----------------------+4.2.1 job-priority (integer(1:100))   This attribute specifies a priority for scheduling the Job. A higher   value specifies a higher priority. The value 1 indicates the lowest   possible priority. The value 100 indicates the highest possible   priority.  Among those jobs that are ready to print, a Printer MUST   print all jobs with a priority value of n before printing those with   a priority value of n-1 for all n.   If the Printer object supports this attribute, it MUST always support   the full range from 1 to 100.  No administrative restrictions are   permitted.  This way an end-user can always make full use of the   entire range with any Printer object.  If privileged jobs are   implemented outside IPP/1.1, they MUST have priorities higher than   100, rather than restricting the range available to end-users.   If the client does not supply this attribute and this attribute is   supported by the Printer object, the Printer object MUST use the   value of the Printer object's "job-priority-default" at job   submission time (unlike most Job Template attributes that are used if   necessary at job processing time).   The syntax for the "job-priority-supported" is also integer(1:100).   This single integer value indicates the number of priority levels   supported.  The Printer object MUST take the value supplied by the   client and map it to the closest integer in a sequence of n integersHastings, et al.            Standards Track                    [Page 94]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   values that are evenly distributed over the range from 1 to 100 using   the formula:      roundToNearestInt((100x+50)/n)   where n is the value of "job-priority-supported" and x ranges from 0   through n-1.   For example, if n=1 the sequence of values is 50;  if n=2, the   sequence of values is:  25 and 75;  if n = 3, the sequence of values   is:  17, 50 and 83;  if n = 10, the sequence of values is: 5, 15, 25,   35, 45, 55, 65, 75, 85, and 95;  if n = 100, the sequence of values   is:  1, 2, 3, ... 100.   If the value of the Printer object's "job-priority-supported" is 10   and the client supplies values in the range 1 to 10, the Printer   object maps them to 5, in the range 11 to 20, the Printer object maps   them to 15, etc.4.2.2 job-hold-until (type3 keyword | name (MAX))   This attribute specifies the named time period during which the Job   MUST become a candidate for printing.   Standard keyword values for named time periods are:      'no-hold': immediately, if there are not other reasons to hold the         job      'indefinite':  - the job is held indefinitely, until a client         performs a Release-Job (section 3.3.6)      'day-time': during the day      'evening': evening      'night': night      'weekend': weekend      'second-shift': second-shift (after close of business)      'third-shift': third-shift (after midnight)   An administrator MUST associate allowable print times with a named   time period (by means outside the scope of this IPP/1.1 document).   An administrator is encouraged to pick names that suggest the type of   time period. An administrator MAY define additional values using the   'name' or 'keyword' attribute syntax, depending on implementation.   If the value of this attribute specifies a time period that is in the   future, the Printer SHOULD add the 'job-hold-until-specified' value   to the job's "job-state-reasons" attribute, MUST move the job to theHastings, et al.            Standards Track                    [Page 95]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   'pending-held' state, and MUST NOT schedule the job for printing   until the specified time-period arrives.   When the specified time period arrives, the Printer MUST remove the   'job-hold-until-specified' value from the job's "job-state-reason"   attribute, if present.  If there are no other job state reasons that   keep the job in the 'pending-held' state, the Printer MUST consider   the job as a candidate for processing by moving the job to the   'pending' state.   If this job attribute value is the named value 'no-hold', or the   specified time period has already started, the job MUST be a   candidate for processing immediately.   If the client does not supply this attribute and this attribute is   supported by the Printer object, the Printer object MUST use the   value of the Printer object's "job-hold-until-default" at job   submission time (unlike most Job Template attributes that are used if   necessary at job processing time).4.2.3 job-sheets (type3 keyword | name(MAX))   This attribute determines which job start/end sheet(s), if any, MUST   be printed with a job.   Standard keyword values are:      'none': no job sheet is printed      'standard': one or more site specific standard job sheets are         printed, e.g. a single start sheet or both start and end sheet is         printed   An administrator MAY define additional values using the 'name' or   'keyword' attribute syntax, depending on implementation.   The effect of this attribute on jobs with multiple documents MAY be   affected by the "multiple-document-handling" job attribute (section4.2.4), depending on the job sheet semantics.4.2.4 multiple-document-handling (type2 keyword)   This attribute is relevant only if a job consists of two or more   documents. This attribute MUST be supported with at least one value   if the Printer supports multiple documents per job (see sections   3.2.4 and 3.3.1).  The attribute controls finishing operations and   the placement of one or more print-stream pages into impressions and   onto media sheets.  When the value of the "copies" attribute exceeds   1, it also controls the order in which the copies that result fromHastings, et al.            Standards Track                    [Page 96]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   processing the documents are produced. For the purposes of this   explanations, if "a" represents an instance of document data, then   the result of processing the data in document "a" is a sequence of   media sheets represented by "a(*)".   Standard keyword values are:      'single-document': If a Job object has multiple documents, say,         the document data is called a and b, then the result of         processing all the document data (a and then b) MUST be treated         as a single sequence of media sheets for finishing operations;         that is, finishing would be performed on the concatenation of         the sequences a(*),b(*).  The Printer object MUST NOT force the         data in each document instance to be formatted onto a new         print-stream page, nor to start a new impression on a new media         sheet. If more than one copy is made, the ordering of the sets         of media sheets resulting from processing the document data         MUST be a(*), b(*), a(*), b(*), start on a new media sheet.      'separate-documents-uncollated-copies': If a Job object has         multiple documents, say, the document data is called a and b,         then the result of processing the data in each document         instance MUST be treated as a single sequence of media sheets         for finishing operations; that is, the sets a(*) and b(*) would         each be finished separately. The Printer object MUST force each         copy of the result of processing the data in a single document         to start on a new media sheet. If more than one copy is made,         the ordering of the sets of media sheets resulting from         processing the document data MUST be a(*), a(*), ..., b(*),         b(*) ... .      'separate-documents-collated-copies': If a Job object has multiple         documents, say, the document data is called a and b, then the         result of processing the data in each document instance MUST be         treated as a single sequence of media sheets for finishing         operations; that is, the sets a(*) and b(*) would each be         finished separately. The Printer object MUST force each copy of         the result of processing the data in a single document to start         on a new media sheet.  If more than one copy is made, the         ordering of the sets of media sheets resulting from processing         the document data MUST be a(*), b(*), a(*), b(*), ... .      'single-document-new-sheet':  Same as 'single-document', except         that the Printer object MUST ensure that the first impression         of each document instance in the job is placed on a new media         sheet.  This value allows multiple documents to be stapled         together with a single staple where each document starts on a         new sheet.Hastings, et al.            Standards Track                    [Page 97]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The 'single-document' value is the same as 'separate-documents-   collated-copies' with respect to ordering of print-stream pages, but   not media sheet generation, since 'single-document' will put the   first page of the next document on the back side of a sheet if an odd   number of pages have been produced so far for the job, while   'separate-documents-collated- copies' always forces the next document   or document copy on to a new sheet.  In addition, if the "finishings"   attribute specifies 'staple', then with 'single-document', documents   a and b are stapled together as a single document with no regard to   new sheets, with 'single-document-new-sheet', documents a and b are   stapled together as a single document, but document b starts on a new   sheet, but with 'separate-documents-uncollated-copies' and   'separate-documents-collated-copies', documents a and b are stapled   separately.   Note: None of these values provide means to produce uncollated sheets   within a document, i.e., where multiple copies of sheet n are   produced before sheet n+1 of the same document.   The relationship of this attribute and the other attributes that   control document processing is described insection 15.3.4.2.5 copies (integer(1:MAX))   This attribute specifies the number of copies to be printed.   On many devices the supported number of collated copies will be   limited by the number of physical output bins on the device, and may   be different from the number of uncollated copies which can be   supported.   Note: The effect of this attribute on jobs with multiple documents is   controlled by the "multiple-document-handling" job attribute (section4.2.4) and the relationship of this attribute and the other   attributes that control document processing is described insection15.3.4.2.6 finishings (1setOf type2 enum)   This attribute identifies the finishing operations that the Printer   uses for each copy of each printed document in the Job. For Jobs with   multiple documents, the "multiple-document-handling" attribute   determines what constitutes a "copy" for purposes of finishing.Hastings, et al.            Standards Track                    [Page 98]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Standard enum values are:   Value  Symbolic Name and Description   '3'    'none':  Perform no finishing   '4'    'staple':  Bind the document(s) with one or more staples. The             exact number and placement of the staples is site-             defined.   '5'    'punch':  This value indicates that holes are required in the             finished document. The exact number and placement of the             holes is site-defined  The punch specification MAY be             satisfied (in a site- and implementation-specific manner)             either by drilling/punching, or by substituting pre-             drilled media.   '6'    'cover':  This value is specified when it is desired to select             a non-printed (or pre-printed) cover for the document.             This does not supplant the specification of a printed             cover (on cover stock medium) by the document itself.   '7'    'bind':  This value indicates that a binding is to be applied             to the document; the type and placement of the binding is             site-defined.   '8'    'saddle-stitch':  Bind the document(s) with one or more             staples (wire stitches) along the middle fold.  The exact             number and placement of the staples and the middle fold             is implementation and/or site-defined.   '9'    'edge-stitch':  Bind the document(s) with one or more staples             (wire stitches) along one edge.  The exact number and             placement of the staples is implementation and/or site-             defined.   '10'-'19'   reserved for future generic finishing enum values.   The following values are more specific; they indicate a corner or an   edge as if the document were a portrait document (see below):   '20'   'staple-top-left':  Bind the document(s) with one or more             staples in the top left corner.   '21'   'staple-bottom-left':  Bind the document(s) with one or more             staples in the bottom left corner.   '22'   'staple-top-right':  Bind the document(s) with one or more             staples in the top right corner.   '23'   'staple-bottom-right':  Bind the document(s) with one or more             staples in the bottom right corner.   '24'   'edge-stitch-left':  Bind the document(s) with one or more             staples (wire stitches) along the left edge.  The exact             number and placement of the staples is implementation             and/or site-defined.Hastings, et al.            Standards Track                    [Page 99]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   '25'   'edge-stitch-top':  Bind the document(s) with one or more             staples (wire stitches) along the top edge.  The exact             number and placement of the staples is implementation             and/or site-defined.   '26'   'edge-stitch-right':  Bind the document(s) with one or more             staples (wire stitches) along the right edge.  The exact             number and placement of the staples is implementation             and/or site-defined.   '27'   'edge-stitch-bottom':  Bind the document(s) with one or more             staples (wire stitches) along the bottom edge.  The exact             number and placement of the staples is implementation             and/or site-defined.   '28'   'staple-dual-left':  Bind the document(s) with two staples             (wire stitches) along the left edge assuming a portrait             document (see above).   '29'   'staple-dual-top':  Bind the document(s) with two staples             (wire stitches) along the top edge assuming a portrait             document (see above).   '30'   'staple-dual-right':  Bind the document(s) with two staples             (wire stitches) along the right edge assuming a portrait             document (see above).   '31'   'staple-dual-bottom':  Bind the document(s) with two staples             (wire stitches) along the bottom edge assuming a portrait             document (see above).   The 'staple-xxx' values are specified with respect to the document as   if the document were a portrait document.  If the document is   actually a landscape or a reverse-landscape document, the client   supplies the appropriate transformed value.  For example, to position   a staple in the upper left hand corner of a landscape document when   held for reading, the client supplies the 'staple-bottom-left' value   (since landscape is defined as a +90 degree rotation of the image   with respect to the media from portrait, i.e., anti-clockwise).  On   the other hand, to position a staple in the upper left hand corner of   a reverse-landscape document when held for reading, the client   supplies the 'staple-top-right' value (since reverse-landscape is   defined as a -90 degree rotation of the image with respect to the   media from portrait, i.e., clockwise).   The angle (vertical, horizontal, angled) of each staple with respect   to the document depends on the implementation which may in turn   depend on the value of the attribute.   Note: The effect of this attribute on jobs with multiple documents is   controlled by the "multiple-document-handling" job attribute (section4.2.4) and the relationship of this attribute and the other   attributes that control document processing is described insection15.3.Hastings, et al.            Standards Track                   [Page 100]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   If the client supplies a value of 'none' along with any other   combination of values, it is the same as if only that other   combination of values had been supplied (that is the 'none' value has   no effect).4.2.7 page-ranges (1setOf rangeOfInteger (1:MAX))   This attribute identifies the range(s) of print-stream pages that the   Printer object uses for each copy of each document which are to be   printed.  Nothing is printed for any pages identified that do not   exist in the document(s).  Ranges MUST be in ascending order, for   example: 1-3, 5-7, 15-19 and MUST NOT overlap, so that a non-spooling   Printer object can process the job in a single pass.  If the ranges   are not ascending or are overlapping, the IPP object MUST reject the   request and return the 'client-error-bad-request' status code.  The   attribute is associated with print-stream pages not application-   numbered pages (for example, the page numbers found in the headers   and or footers for certain word processing applications).   For Jobs with multiple documents, the "multiple-document-handling"   attribute determines what constitutes a "copy" for purposes of the   specified page range(s).  When "multiple-document-handling" is   'single-document', the Printer object MUST apply each supplied page   range once to the concatenation of the print-stream pages.  For   example, if there are 8 documents of 10 pages each, the page-range   '41:60' prints the pages in the 5th and 6th documents as a single   document and none of the pages of the other documents are printed.   When "multiple-document- handling" is 'separate-documents-   uncollated-copies' or 'separate-documents-collated-copies', the   Printer object MUST apply each supplied page range repeatedly to each   document copy.  For the same job, the page-range '1:3, 10:10' would   print the first 3 pages and the 10th page of each of the 8 documents   in the Job, as 8 separate documents.   In most cases, the exact pages to be printed will be generated by a   device driver and this attribute would not be required.  However,   when printing an archived document which has already been formatted,   the end user may elect to print just a subset of the pages contained   in the document.  In this case, if page-range = n.m is specified, the   first page to be printed will be page n. All subsequent pages of the   document will be printed through and including page m.   "page-ranges-supported" is a boolean value indicating whether or not   the printer is capable of supporting the printing of page ranges.   This capability may differ from one PDL to another. There is no   "page-ranges-default" attribute.  If the "page-ranges" attribute is   not supplied by the client, all pages of the document will be   printed.Hastings, et al.            Standards Track                   [Page 101]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Note: The effect of this attribute on jobs with multiple documents is   controlled by the "multiple-document-handling" job attribute (section4.2.4) and the relationship of this attribute and the other   attributes that control document processing is described insection15.3.4.2.8 sides (type2 keyword)   This attribute specifies how print-stream pages are to be imposed   upon the sides of an instance of a selected medium, i.e., an   impression.   The standard keyword values are:      'one-sided': imposes each consecutive print-stream page upon the         same side of consecutive media sheets.      'two-sided-long-edge': imposes each consecutive pair of print-         stream pages upon front and back sides of consecutive media         sheets, such that the orientation of each pair of print-stream         pages on the medium would be correct for the reader as if for         binding on the long edge.  This imposition is sometimes called         'duplex' or 'head-to-head'.      'two-sided-short-edge': imposes each consecutive pair of print-         stream pages upon front and back sides of consecutive media         sheets, such that the orientation of each pair of print-stream         pages on the medium would be correct for the reader as if for         binding on the short edge.  This imposition is sometimes called         'tumble' or 'head-to-toe'.      'two-sided-long-edge', 'two-sided-short-edge',         'tumble', and 'duplex' all work the same for portrait or         landscape.  However         'head-to-toe' is      'tumble' in portrait but 'duplex' in landscape.  'head-to-head'         also switches between 'duplex' and 'tumble' when using portrait         and landscape modes.   Note: The effect of this attribute on jobs with multiple documents is   controlled by the "multiple-document-handling" job attribute (section4.2.4) and the relationship of this attribute and the other   attributes that control document processing is described insection15.3.4.2.9 number-up (integer(1:MAX))   This attribute specifies the number of print-stream pages to impose   upon a single side of an instance of a selected medium.  For example,   if the value is:Hastings, et al.            Standards Track                   [Page 102]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Value  Description   '1'    the Printer MUST place one print-stream page on a single side             of an instance of the selected medium (MAY add some sort             of translation, scaling, or rotation).   '2'    the Printer MUST place two print-stream pages on a single side             of an instance of the selected medium (MAY add some sort             of translation, scaling, or rotation).   '4'    the Printer MUST place four print-stream pages on a single             side of an instance of the selected medium (MAY add some             sort of translation, scaling, or rotation).   This attribute primarily controls the translation, scaling and   rotation of print-stream pages.   Note: The effect of this attribute on jobs with multiple documents is   controlled by the "multiple-document-handling" job attribute (section4.2.4) and the relationship of this attribute and the other   attributes that control document processing is described insection15.3.4.2.10 orientation-requested (type2 enum)   This attribute indicates the desired orientation for printed print-   stream pages; it does not describe the orientation of the client-   supplied print-stream pages.   For some document formats (such as 'application/postscript'), the   desired orientation of the print-stream pages is specified within the   document data.  This information is generated by a device driver   prior to the submission of the print job.  Other document formats   (such as 'text/plain') do not include the notion of desired   orientation within the document data.  In the latter case it is   possible for the Printer object to bind the desired orientation to   the document data after it has been submitted.  It is expected that a   Printer object would only support "orientations-requested" for some   document formats (e.g., 'text/plain' or 'text/html') but not others   (e.g., 'application/postscript').  This is no different than any   other Job Template attribute sincesection 4.2, item 1, points out   that a Printer object may support or not support any Job Template   attribute based on the document format supplied by the client.   However, a special mention is made here since it is very likely that   a Printer object will support "orientation-requested" for only a   subset of the supported document formats.Hastings, et al.            Standards Track                   [Page 103]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Standard enum values are:   Value  Symbolic Name and Description   '3'    'portrait':  The content will be imaged across the short edge             of the medium.   '4'    'landscape':  The content will be imaged across the long edge             of the medium.  Landscape is defined to be a rotation of             the print-stream page to be imaged by +90 degrees with             respect to the medium (i.e. anti-clockwise) from the             portrait orientation.  Note:  The +90 direction was             chosen because simple finishing on the long edge is the             same edge whether portrait or landscape   '5'    'reverse-landscape':  The content will be imaged across the             long edge of the medium.  Reverse-landscape is defined to             be a rotation of the print-stream page to be imaged by -             90 degrees with respect to the medium (i.e. clockwise)             from the portrait orientation.  Note: The 'reverse-             landscape' value was added because some applications             rotate landscape -90 degrees from portrait, rather than             +90 degrees.   '6'    'reverse-portrait':  The content will be imaged across the             short edge of the medium.  Reverse-portrait is defined to             be a rotation of the print-stream page to be imaged by             180 degrees with respect to the medium from the portrait             orientation.  Note: The 'reverse-portrait' value was             added for use with the "finishings" attribute in cases             where the opposite edge is desired for finishing a             portrait document on simple finishing devices that have             only one finishing position.  Thus a 'text'/plain'             portrait document can be stapled "on the right" by a             simple finishing device as is common use with some middle             eastern languages such as Hebrew.   Note: The effect of this attribute on jobs with multiple documents is   controlled by the "multiple-document-handling" job attribute (section4.2.4) and the relationship of this attribute and the other   attributes that control document processing is described insection15.3.4.2.11 media (type3 keyword | name(MAX))   This attribute identifies the medium that the Printer uses for all   impressions of the Job.   The values for "media" include medium-names, medium-sizes, input-   trays and electronic forms so that one attribute specifies the media.   If a Printer object supports a medium name as a value of thisHastings, et al.            Standards Track                   [Page 104]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   attribute, such a medium name implicitly selects an input-tray that   contains the specified medium.  If a Printer object supports a medium   size as a value of this attribute, such a medium size implicitly   selects a medium name that in turn implicitly selects an input-tray   that contains the medium with the specified size.  If a Printer   object supports an input-tray as the value of this attribute, such an   input-tray implicitly selects the medium that is in that input-tray   at the time the job prints.  This case includes manual-feed input-   trays.  If a Printer object supports an electronic form as the value   of this attribute, such an electronic form implicitly selects a   medium-name that in turn implicitly selects an input-tray that   contains the medium specified by the electronic form.  The electronic   form also implicitly selects an image that the Printer MUST merge   with the document data as its prints each page.   Standard keyword values are taken from ISO DPA [ISO10175], the   Printer MIB [RFC1759], and ASME-Y14.1M [ASME-Y14.1M] and are listed   insection 14.  An administrator MAY define additional values using   the 'name' or 'keyword' attribute syntax, depending on   implementation.   There is also an additional Printer attribute named "media-ready"   which differs from "media-supported" in that legal values only   include the subset of "media-supported" values that are physically   loaded and ready for printing with no operator intervention required.   If an IPP object supports "media-supported", it NEED NOT support   "media-ready".   The relationship of this attribute and the other attributes that   control document processing is described insection 15.3.4.2.12 printer-resolution (resolution)   This attribute identifies the resolution that Printer uses for the   Job.4.2.13 print-quality (type2 enum)   This attribute specifies the print quality that the Printer uses for   the Job.   The standard enum values are:   Value  Symbolic Name and Description   '3'    'draft': lowest quality available on the printer   '4'    'normal': normal or intermediate quality on the printer   '5'    'high': highest quality available on the printerHastings, et al.            Standards Track                   [Page 105]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.3 Job Description Attributes   The attributes in this section form the attribute group called "job-   description".  The following table summarizes these attributes.  The   third column indicates whether the attribute is a REQUIRED attribute   that MUST be supported by Printer objects.  If it is not indicated as   REQUIRED, then it is OPTIONAL.  The maximum size in octets for 'text'   and 'name' attributes is indicated in parenthesizes.   +----------------------------+----------------------+--------------+   |      Attribute             |     Syntax           |   REQUIRED?  |   +----------------------------+----------------------+--------------+   | job-uri                    | uri                  |  REQUIRED    |   +----------------------------+----------------------+--------------+   | job-id                     | integer(1:MAX)       |  REQUIRED    |   +----------------------------+----------------------+--------------+   | job-printer-uri            | uri                  |  REQUIRED    |   +----------------------------+----------------------+--------------+   | job-more-info              | uri                  |              |   +----------------------------+----------------------+--------------+   | job-name                   | name (MAX)           |  REQUIRED    |   +----------------------------+----------------------+--------------+   | job-originating-user-name  | name (MAX)           |  REQUIRED    |   +----------------------------+----------------------+--------------+   | job-state                  | type1 enum           |  REQUIRED    |   +----------------------------+----------------------+--------------+   | job-state-reasons          | 1setOf type2 keyword |  REQUIRED    |   +----------------------------+----------------------+--------------+   | job-state-message          | text (MAX)           |              |   +----------------------------+----------------------+--------------+   | job-detailed-status-       | 1setOf text (MAX)    |              |   |       messages             |                      |              |   +----------------------------+----------------------+--------------+   | job-document-access-errors | 1setOf text (MAX)    |              |   +----------------------------+----------------------+--------------+   | number-of-documents        | integer (0:MAX)      |              |   +----------------------------+----------------------+--------------+   | output-device-assigned     | name (127)           |              |   +----------------------------+----------------------+--------------+   | time-at-creation           | integer (MIN:MAX)    |  REQUIRED    |   +----------------------------+----------------------+--------------+   | time-at-processing         | integer (MIN:MAX)    |  REQUIRED    |   +----------------------------+----------------------+--------------+   | time-at-completed          | integer (MIN:MAX)    |  REQUIRED    |   +----------------------------+----------------------+--------------+   | job-printer-up-time        | integer (1:MAX)      |  REQUIRED    |   +----------------------------+----------------------+--------------+   | date-time-at-creation      | dateTime             |              |Hastings, et al.            Standards Track                   [Page 106]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   +----------------------------+----------------------+--------------+   | date-time-at-processing    | dateTime             |              |   +----------------------------+----------------------+--------------+   | date-time-at-completed     | dateTime             |              |   +----------------------------+----------------------+--------------+   | number-of-intervening-jobs | integer (0:MAX)      |              |   +----------------------------+----------------------+--------------+   | job-message-from-operator  | text (127)           |              |   +----------------------------+----------------------+--------------+   | job-k-octets               | integer (0:MAX)      |              |   +----------------------------+----------------------+--------------+   | job-impressions            | integer (0:MAX)      |              |   +----------------------------+----------------------+--------------+   | job-media-sheets           | integer (0:MAX)      |              |   +----------------------------+----------------------+--------------+   | job-k-octets-processed     | integer (0:MAX)      |              |   +----------------------------+----------------------+--------------+   | job-impressions-completed  | integer (0:MAX)      |              |   +----------------------------+----------------------+--------------+   | job-media-sheets-completed | integer (0:MAX)      |              |   +----------------------------+----------------------+--------------+   | attributes-charset         | charset              |  REQUIRED    |   +----------------------------+----------------------+--------------+   | attributes-natural-language| naturalLanguage      |  REQUIRED    |   +----------------------------+----------------------+--------------+4.3.1 job-uri (uri)   This REQUIRED attribute contains the URI for the job.  The Printer   object, on receipt of a new job, generates a URI which identifies the   new Job.  The Printer object returns the value of the "job-uri"   attribute as part of the response to a create request.  The precise   format of a Job URI is implementation dependent.  If the Printer   object supports more than one URI and there is some relationship   between the newly formed Job URI and the Printer object's URI, the   Printer object uses the Printer URI supplied by the client in the   create request.  For example, if the create request comes in over a   secure channel, the new Job URI MUST use the same secure channel.   This can be guaranteed because the Printer object is responsible for   generating the Job URI and the Printer object is aware of its   security configuration and policy as well as the Printer URI used in   the create request.   For a description of this attribute and its relationship to "job-id"   and "job-printer-uri" attribute, see the discussion insection 2.4 on   "Object Identity".Hastings, et al.            Standards Track                   [Page 107]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.3.2 job-id (integer(1:MAX))   This REQUIRED attribute contains the ID of the job.  The Printer, on   receipt of a new job, generates an ID which identifies the new Job on   that Printer.  The Printer returns the value of the "job-id"   attribute as part of the response to a create request.  The 0 value   is not included to allow for compatibility with SNMP index values   which also cannot be 0.   For a description of this attribute and its relationship to "job-uri"   and "job-printer-uri" attribute, see the discussion insection 2.4 on   "Object Identity".4.3.3 job-printer-uri (uri)   This REQUIRED attribute identifies the Printer object that created   this Job object.  When a Printer object creates a Job object, it   populates this attribute with the Printer object URI that was used in   the create request.  This attribute permits a client to identify the   Printer object that created this Job object when only the Job   object's URI is available to the client.  The client queries the   creating Printer object to determine which languages, charsets,   operations, are supported for this Job.   For a description of this attribute and its relationship to "job-uri"   and "job-id" attribute, see the discussion insection 2.4 on "Object   Identity".4.3.4 job-more-info (uri)   Similar to "printer-more-info", this attribute contains the URI   referencing some resource with more information about this Job   object, perhaps an HTML page containing information about the Job.4.3.5 job-name (name(MAX))   This REQUIRED attribute is the name of the job.  It is a name that is   more user friendly than the "job-uri" attribute value.  It does not   need to be unique between Jobs.  The Job's "job-name" attribute is   set to the value supplied by the client in the "job-name" operation   attribute in the create request (seeSection 3.2.1.1).   If, however,   the "job-name" operation attribute is not supplied by the client in   the create request, the Printer object, on creation of the Job, MUST   generate a name.  The printer SHOULD generate the value of the Job's   "job-name" attribute from the first of the following sources that   produces a value: 1) the "document-name" operation attribute of theHastings, et al.            Standards Track                   [Page 108]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   first (or only) document, 2) the "document-URI" attribute of the   first (or only) document, or 3) any other piece of Job specific   and/or Document Content information.4.3.6 job-originating-user-name (name(MAX))   This REQUIRED attribute contains the name of the end user that   submitted the print job.  The Printer object sets this attribute to   the most authenticated printable name that it can obtain from the   authentication service over which the IPP operation was received.   Only if such is not available, does the Printer object use the value   supplied by the client in the "requesting-user-name" operation   attribute of the create operation (see Sections4.4.2,4.4.3, and8).   Note:  The Printer object needs to keep an internal originating user   id of some form, typically as a credential of a principal, with the   Job object.  Since such an internal attribute is implementation-   dependent and not of interest to clients, it is not specified as a   Job Description attribute.  This originating user id is used for   authorization checks (if any) on all subsequent operations.4.3.7 job-state (type1 enum)   This REQUIRED attribute identifies the current state of the job.   Even though the IPP protocol defines seven values for job states   (plus the out-of-band 'unknown' value - seeSection 4.1),   implementations only need to support those states which are   appropriate for the particular implementation.  In other words, a   Printer supports only those job states implemented by the output   device and available to the Printer object implementation.   Standard enum values are:   Values Symbolic Name and Description   '3'  'pending':  The job is a candidate to start processing, but is           not yet processing.   '4'  'pending-held':  The job is not a candidate for processing for           any number of reasons but will return to the 'pending'           state as soon as the reasons are no longer present.  The           job's "job-state-reason" attribute MUST indicate why the           job is no longer a candidate for processing.Hastings, et al.            Standards Track                   [Page 109]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   '5'  'processing':  One or more of:           1.  the job is using, or is attempting to use, one or           more purely software processes that are analyzing,           creating, or interpreting a PDL, etc.,           2.  the job is using, or is attempting to use, one or           more hardware devices that are interpreting a PDL, making           marks on a medium, and/or performing finishing, such as           stapling, etc.,           3. the Printer object has made the job ready for           printing, but the output device is not yet printing it,           either because the job hasn't reached the output device           or because the job is queued in the output device or some           other spooler, awaiting the output device to print it.           When the job is in the 'processing' state, the entire job           state includes the detailed status represented in the           Printer object's "printer-state", "printer-state-           reasons", and "printer-state-message" attributes.           Implementations MAY, though they NEED NOT,  include           additional values in the job's "job-state-reasons"           attribute to indicate the progress of the job, such as           adding the 'job-printing' value to indicate when the           output device is actually making marks on paper and/or           the 'processing-to-stop-point' value to indicate that the           IPP object is in the process of canceling or aborting the           job.  Most implementations won't bother with this nuance.   '6'  'processing-stopped':  The job has stopped while processing           for any number of reasons and will return to the           'processing' state as soon as the reasons are no longer           present.           The job's "job-state-reason" attribute MAY indicate why           the job has stopped processing.  For example, if the           output device is stopped, the 'printer-stopped' value MAY           be included in the job's "job-state-reasons" attribute.           Note:  When an output device is stopped, the device           usually indicates its condition in human readable form           locally at the device.  A client can obtain more complete           device status remotely by querying the Printer object's           "printer-state", "printer-state-reasons" and "printer-           state-message" attributes.   '7'  'canceled':  The job has been canceled by a Cancel-Job           operation and the Printer object has completed cancelingHastings, et al.            Standards Track                   [Page 110]

RFC 2911              IPP/1.1: Model and Semantics        September 2000           the job and all job status attributes have reached their           final values for the job.  While the Printer object is           canceling the job, the job remains in its current state,           but the job's "job-state-reasons" attribute SHOULD           contain the 'processing-to-stop-point' value and one of           the 'canceled-by-user', 'canceled-by-operator', or           'canceled-at-device' value.  When the job moves to the           'canceled' state, the  'processing-to-stop-point' value,           if present, MUST be removed, but the 'canceled-by-xxx',           if present, MUST remain.   '8'  'aborted':  The job has been aborted by the system, usually           while the job was in the 'processing' or 'processing-           stopped' state and the Printer has completed aborting the           job and all job status attributes have reached their           final values for the job.  While the Printer object is           aborting the job, the job remains in its current state,           but the job's "job-state-reasons" attribute SHOULD           contain the 'processing-to-stop-point' and 'aborted-by-           system' values.  When the job moves to the 'aborted'           state, the  'processing-to-stop-point' value, if present,           MUST be removed, but the 'aborted-by-system' value, if           present, MUST remain.   '9'  'completed':  The job has completed successfully or with           warnings or errors after processing and all of the job           media sheets have been successfully stacked in the           appropriate output bin(s) and all job status attributes           have reached their final values for the job.  The job's           "job-state-reasons" attribute SHOULD contain one of:           'completed-successfully', 'completed-with-warnings', or           'completed-with-errors' values.   The final value for this attribute MUST be one of: 'completed',   'canceled', or 'aborted' before the Printer removes the job   altogether.  The length of time that jobs remain in the 'canceled',   'aborted', and 'completed' states depends on implementation.  Seesection 4.3.7.2.   The following figure shows the normal job state transitions.                                                      +----> canceled                                                     /       +----> pending --------> processing ---------+------> completed       |         ^                   ^               \   --->+         |                   |                +----> aborted       |         v                   v               /       +----> pending-held    processing-stopped ---+Hastings, et al.            Standards Track                   [Page 111]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Normally a job progresses from left to right.  Other state   transitions are unlikely, but are not forbidden.  Not shown are the   transitions to the 'canceled' state from the 'pending', 'pending-   held', and 'processing-stopped' states.   Jobs reach one of the three terminal states: 'completed', 'canceled',   or 'aborted', after the jobs have completed all activity, including   stacking output media, after the jobs have completed all activity,   and all job status attributes have reached their final values for the   job.4.3.7.1 Forwarding Servers   As with all other IPP attributes, if the implementation cannot   determine the correct value for this attribute, it SHOULD respond   with the out-of-band value 'unknown' (seesection 4.1) rather than   try to guess at some possibly incorrect value and give the end user   the wrong impression about the state of the Job object.  For example,   if the implementation is just a gateway into some printing system   from which it can normally get status, but temporarily is unable,   then the implementation should return the 'unknown' value.  However,   if the implementation is a gateway to a printing system that never   provides detailed status about the print job, the implementation MAY   set the IPP Job object's state  to 'completed', provided that it also   sets the 'queued-in-device' value in the job's "job-state-reasons"   attribute (seesection 4.3.8).4.3.7.2 Partitioning of Job States   This section partitions the 7 job states into phases:  Job Not   Completed, Job Retention, Job History, and Job Removal.  This section   also explains the 'job-restartable' value of the "job-state-reasons"   Job Description attribute for use with the Restart-Job operation.   Job Not Completed:  When a job is in the 'pending', 'pending-held',   'processing', or 'processing-stopped' states, the job is not   completed.   Job Retention:  When a job enters one of the three terminal job   states:  'completed', 'canceled', or 'aborted', the IPP Printer   object MAY "retain" the job in a restartable condition for an   implementation-defined time period.  This time period MAY be zero   seconds and MAY depend on the terminal job state.  This phase is   called Job Retention.  While in the Job Retention phase, the job's   document data is retained and a client may restart the job using the   Restart-Job operation.  If the IPP object supports the Restart-JobHastings, et al.            Standards Track                   [Page 112]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   operation, then it SHOULD indicate that the job is restartable by   adding the 'job-restartable' value to the job's "job-state-reasons"   attribute (seeSection 4.3.8) during the Job Retention phase.   Job History:  After the Job Retention phase expires for a job, the   Printer object deletes the document data for the job and the job   becomes part of the Job History.  The Printer object MAY also delete   any number of the job attributes.  Since the job is no longer   restartable, the Printer object MUST remove the 'job-restartable'   value from the job's "job-state-reasons" attribute, if present.   Job Removal:  After the job has remained in the Job History for an   implementation-defined time, such as when the number of jobs exceeds   a fixed number or after a fixed time period (which MAY be zero   seconds), the IPP Printer removes the job from the system.   Using the Get-Jobs operation and supplying the 'not-completed' value   for the "which-jobs" operation attribute, a client is requesting jobs   in the Job Not Completed phase.  Using the Get-Jobs operation and   supplying the 'completed' value for the "which-jobs" operation   attribute, a client is requesting jobs in the Job Retention and Job   History phases.  Using the Get-Job-Attributes operation, a client is   requesting a job in any phase except Job Removal.  After Job Removal,   the Get-Job-Attributes and Get-Jobs operations no longer are capable   of returning any information about a job.4.3.8 job-state-reasons (1setOf type2 keyword)   This REQUIRED attribute provides additional information about the   job's current state, i.e., information that augments the value of the   job's "job-state" attribute.   These values MAY be used with any job state or states for which the   reason makes sense.  Some of these value definitions indicate   conformance requirements; the rest are OPTIONAL.  Furthermore, when   implemented, the Printer MUST return these values when the reason   applies and MUST NOT return them when the reason no longer applies   whether the value of the Job's "job-state" attribute changed or not.   When the Job does not have any reasons for being in its current   state, the value of the Job's "job-state-reasons" attribute MUST be   'none'.   Note: While values cannot be added to the 'job-state' attribute   without impacting deployed clients that take actions upon receiving   "job-state" values, it is the intent that additional "job-state-   reasons" values can be defined and registered without impacting such   deployed clients.  In other words, the "job-state-reasons" attribute   is intended to be extensible.Hastings, et al.            Standards Track                   [Page 113]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The following standard keyword values are defined.  For ease of   understanding, the values are presented in the order in which the   reasons are likely to occur (if implemented), starting with the   'job-incoming' value:      'none':  There are no reasons for the job's current state.  This         state reason is semantically equivalent to "job-state-reasons"         without any value and MUST be used when there is no other         value, since the 1setOf attribute syntax requires at least one         value.      'job-incoming':  Either (1) the Printer has accepted the Create-         Job operation and is expecting additional Send-Document and/or         Send-URI operations, or (2) the Printer is retrieving/accepting         document data as a result of a Print-Job, Print-URI, Send-         Document or Send-URI operation.      'job-data-insufficient':  The Create-Job operation has been         accepted by the Printer, but the Printer is expecting         additional document data before it can move the job into the         'processing' state.  If a Printer starts processing before it         has received all data, the Printer removes the 'job-data-         insufficient' reason, but the 'job-incoming' remains.  If a         Printer starts processing after it has received all data, the         Printer removes the 'job-data-insufficient' reason and the         'job-incoming' at the same time.      'document-access-error':  After accepting a Print-URI or Send-URI         request, the Printer could not access one or more documents         passed by reference.  This reason is intended to cover any file         access problem, including file does not exist and access denied         because of an access control problem.  The Printer MAY also         indicate the document access error using the "job-document-         access-errors" Job Description attribute (seesection 4.3.11).         Whether the Printer aborts the job and moves the job to the         'aborted' job state or prints all documents that are accessible         and moves the job to the 'completed' job state and adds the         'completed-with-errors' value in the job's "job-state-reasons"         attribute depends on implementation and/or site policy.  This         value SHOULD be supported if the Print-URI or Send-URI         operations are supported.      'submission-interrupted':  The job was not completely submitted         for some unforeseen reason, such as: (1) the Printer has         crashed before the job was closed by the client, (2) the         Printer or the document transfer method has crashed in some         non-recoverable way before the document data was entirely         transferred to the Printer, (3) the client crashed or failed to         close the job before the time-out period.  Seesection 4.4.31.      'job-outgoing':  The Printer is transmitting the job to the output         device.Hastings, et al.            Standards Track                   [Page 114]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      'job-hold-until-specified':  The value of the job's "job-hold-         until" attribute was specified with a time period that is still         in the future.  The job MUST NOT be a candidate for processing         until this reason is removed and there are no other reasons to         hold the job.  This value SHOULD be supported if the "job-         hold-until" Job Template attribute is supported.      'resources-are-not-ready':  At least one of the resources needed         by the job, such as media, fonts, resource objects, etc., is         not ready on any of the physical printer's for which the job is         a candidate.  This condition MAY be detected when the job is         accepted, or subsequently while the job is pending or         processing, depending on implementation.  The job may remain in         its current state or be moved to the 'pending-held' state,         depending on implementation and/or job scheduling policy.      'printer-stopped-partly':  The value of the Printer's "printer-         state-reasons" attribute contains the value 'stopped-partly'.      'printer-stopped':  The value of the Printer's "printer-state"         attribute is 'stopped'.      'job-interpreting': Job is in the 'processing' state, but more         specifically, the Printer is interpreting the document data.      'job-queued': Job is in the 'processing' state, but more         specifically, the Printer has queued the document data.      'job-transforming': Job is in the 'processing' state, but more         specifically, the Printer is interpreting document data and         producing another electronic representation.      'job-queued-for-marker': Job is in any of the 'pending-held',         'pending', or 'processing' states, but more specifically, the         Printer has completed enough processing of the document to be         able to start marking and the job is waiting for the marker.         Systems that require human intervention to release jobs using         the Release-Job operation, put the job into the 'pending-held'         job state.  Systems that automatically select a job to use the         marker put the job into the  'pending' job state or keep the         job in the 'processing' job state while waiting for the marker,         depending on implementation.  All implementations put the job         into (or back into) the 'processing' state when marking does         begin.      'job-printing':  The output device is marking media. This value is         useful for Printers which spend a great deal of time processing         (1) when no marking is happening and then want to show that         marking is now happening or (2) when the job is in the process         of being canceled or aborted while the job remains in the         'processing' state, but the marking has not yet stopped so that         impression or sheet counts are still increasing for the job.Hastings, et al.            Standards Track                   [Page 115]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      'job-canceled-by-user':  The job was canceled by the owner of the         job using the Cancel-Job request, i.e., by a user whose         authenticated identity is the same as the value of the         originating user that created the Job object, or by some other         authorized end-user, such as a member of the job owner's         security group.  This value SHOULD be supported.      'job-canceled-by-operator':  The job was canceled by the operator         using the Cancel-Job request, i.e., by a user who has been         authenticated as having operator privileges (whether local or         remote).  If the security policy is to allow anyone to cancel         anyone's job, then this value may be used when the job is         canceled by other than the owner of the job.  For such a         security policy, in effect, everyone is an operator as far as         canceling jobs with IPP is concerned.  This value SHOULD be         supported if the implementation permits canceling by other than         the owner of the job.      'job-canceled-at-device':  The job was canceled by an unidentified         local user, i.e., a user at a console at the device.  This         value SHOULD be supported if the implementation supports         canceling jobs at the console.      'aborted-by-system':  The job (1) is in the process of being         aborted, (2) has been aborted by the system and placed in the         'aborted' state, or (3) has been aborted by the system and         placed in the 'pending-held' state, so that a user or operator         can manually try the job again.  This value SHOULD be         supported.      'unsupported-compression': The job was aborted by the system         because the Printer determined while attempting to decompress         the document-data's that the compression is actually not among         those supported by the Printer.  This value MUST be supported,         since "compressions is a REQUIRED operation attribute.      'compression-error': The job was aborted by the system because the         Printer encountered an error in the document-data while         decompressing it.  If the Printer posts this reason, the         document-data has already passed any tests that would have led         to the 'unsupported-compression' job-state-reason.      'unsupported-document-format': The job was aborted by the system         because the document-data's document-format is not among those         supported by the Printer.  If the client specifies the         document-format as 'application/octet-stream', the printer MAY         abort the job and post this reason even though the format is a         member of the "document-format-supported" printer attribute,         but not among the auto-sensed document-formats.  This value         MUST be supported, since "document-format" is a REQUIRED         operation attribute.Hastings, et al.            Standards Track                   [Page 116]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      'document-format-error': The job was aborted by the system because         the Printer encountered an error in the document-data while         processing it.  If the Printer posts this reason, the         document-data has already passed any tests that would have led         to the 'unsupported-document-format' job-state-reason.      'processing-to-stop-point':  The requester has issued a Cancel-Job         operation or the Printer object has aborted the job, but is         still performing some actions on the job until a specified stop         point occurs or job termination/cleanup is completed.         If the implementation requires some measurable time to cancel         the job in the 'processing' or 'processing-stopped' job states,         the IPP object MUST use this value to indicate that the Printer         object is still performing some actions on the job while the         job remains in the 'processing' or 'processing-stopped' state.         After all the job's job description attributes have stopped         incrementing, the Printer object moves the job from the         'processing' state to the 'canceled' or         'aborted' job states.      'service-off-line':  The Printer is off-line and accepting no         jobs.  All 'pending' jobs are put into the 'pending-held'         state.  This situation could be true if the service's or         document transform's input is impaired or broken.      'job-completed-successfully':  The job completed successfully.         This value SHOULD be supported.      'job-completed-with-warnings':  The job completed with warnings.         This value SHOULD be supported if the implementation detects         warnings.      'job-completed-with-errors':  The job completed with errors (and         possibly warnings too).  This value SHOULD be supported if the         implementation detects errors.      'job-restartable' - This job is retained (seesection 4.3.7.2) and         is currently able to be restarted using the Restart-Job         operation (seesection 3.3.7).  If 'job-restartable' is a value         of the job's 'job-state-reasons' attribute, then the IPP object         MUST accept a Restart-Job operation for that job.  This value         SHOULD be supported if the Restart-Job operation is supported.      'queued-in-device': The job has been forwarded to a device or         print system that is unable to send back status.  The Printer         sets the job's "job-state " attribute to 'completed'  and adds         the 'queued-in-device' value to the job's "job-state-reasons"         attribute to indicate that the Printer has no additional         information about the job and never will have any better         information.  Seesection 4.3.7.1.Hastings, et al.            Standards Track                   [Page 117]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.3.9 job-state-message (text(MAX))   This attribute specifies information about the "job-state" and "job-   state-reasons" attributes in human readable text.  If the Printer   object supports this attribute, the Printer object MUST be able to   generate this message in any of the natural languages identified by   the Printer's "generated-natural-language-supported" attribute (see   the "attributes-natural-language" operation attribute specified inSection 3.1.4.1).   The value SHOULD NOT contain additional information not contained in   the values of the "job-state" and "job-states-reasons" attributes,   such as interpreter error information.  Otherwise, application   programs might attempt to parse the (localized text).  For such   additional information such as interpreter errors for application   program consumption or specific document access errors, new   attributes with keyword values, needs to be developed and registered.4.3.10 job-detailed-status-messages (1setOf text(MAX))   This attribute specifies additional detailed and technical   information about the job.  The Printer NEED NOT localize the   message(s), since they are intended for use by the system   administrator or other experienced technical persons.  Localization   might obscure the technical meaning of such messages.  Clients MUST   NOT attempt to parse the value of this attribute.  See "job-   document-access-errors" (section 4.3.11) for additional errors that a   program can process.4.3.11 job-document-access-errors (1setOf text(MAX))   This attribute provides additional information about each document   access error for this job encountered by the Printer after it   returned a response to the Print-URI or Send-URI operation and   subsequently attempted to access document(s) supplied in the Print-   URI or Send-URI operation.  For errors in the protocol that is   identified by the URI scheme in the "document-uri" operation   attribute, such as 'http:' or 'ftp:', the error code is returned in   parentheses, followed by the URI.  For example:      (404)http://ftp.pwg.org/pub/pwg/ipp/new_MOD/ipp-model-v11.pdf   Most Internet protocols use decimal error codes (unlike IPP), so the   ASCII error code representation is in decimal.Hastings, et al.            Standards Track                   [Page 118]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.3.12 number-of-documents (integer(0:MAX))   This attribute indicates the number of documents in the job, i.e.,   the number of Send-Document, Send-URI, Print-Job, or Print-URI   operations that the Printer has accepted for this job, regardless of   whether the document data has reached the Printer object or not.   Implementations supporting the OPTIONAL Create-Job/Send-   Document/Send-URI operations SHOULD support this attribute so that   clients can query the number of documents in each job.4.3.13 output-device-assigned (name(127))   This attribute identifies the output device to which the Printer   object has assigned this job.  If an output device implements an   embedded Printer object, the Printer object NEED NOT set this   attribute.  If a print server implements a Printer object, the value   MAY be empty (zero- length string) or not returned until the Printer   object assigns an output device to the job.  This attribute is   particularly useful when a single Printer object supports multiple   devices (so called "fan-out" - seesection 2.1).4.3.14 Event Time Job Description Attributes   This section defines the Job Description attributes that indicate the   time at which certain events occur for a job.  If the job event has   not yet occurred, then the IPP object MUST return the 'no-value'   out-of-band value (see the beginning ofSection 4.1).  The "time-at-   xxx(integer)" attributes represent time as an 'integer' representing   the number of seconds since the device was powered up (informally   called "time ticks").  The "date-time-at-xxx(dateTime)" attributes   represent time as 'dateTime' representing date and time (including an   offset from UTC).   In order to populate these attributes, the Printer object copies the   value(s) of the following Printer Description attributes at the time   the event occurs:      1. the value in the Printer's "printer-up-time" attribute for the         "time-at-xxx(integer)" attributes      2. the value in the Printer's "printer-current-time" attribute for         the "date-time-at-xxx(dateTime)" attributes.   If the Printer resets its "printer-up-time" attribute to 1 on power-   up (seesection 4.4.29) and has persistent jobs, then it MUST change   all of jobs' "time-at-xxx(integer)" (time tick) job attributes whose   events have occurred either to:Hastings, et al.            Standards Track                   [Page 119]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      1. 0 to indicate that the event happened before the most recent         power up OR      2. the negative of the number of seconds before the most recent         power-up that the event took place, though the negative number         NEED NOT reflect the exact number of seconds.   If a client queries a "time-at-xxx(integer)" time tick Job attribute   and finds the value to be 0 or negative, the client MUST assume that   the event occurred in some life other than the Printer's current   life.   Note: A Printer does not change the values of any "date-time-at-   xxx(dateTime)" job attributes on power-up.4.3.14.1 time-at-creation (integer(MIN:MAX))   This REQUIRED attribute indicates the time at which the Job object   was created.4.3.14.2 time-at-processing (integer(MIN:MAX))   This REQUIRED attribute indicates the time at which the Job object   first began processing after the create operation or the most recent   Restart-Job operation.  The out-of-band 'no-value' value is returned   if the job has not yet been in the 'processing' state (see the   beginning ofSection 4.1).4.3.14.3 time-at-completed (integer(MIN:MAX))   This REQUIRED attribute indicates the time at which the Job object   completed (or was canceled or aborted).  The out-of-band 'no-value'   value is returned if the job has not yet completed, been canceled, or   aborted (see the beginning ofSection 4.1).4.3.14.4 job-printer-up-time (integer(1:MAX))   This REQUIRED Job Description attribute indicates the amount of time   (in seconds) that the Printer implementation has been up and running.   This attribute is an alias for the "printer-up-time" Printer   Description attribute (seeSection 4.4.29).   A client MAY request this attribute in a Get-Job-Attributes or Get-   Jobs request and use the value returned in combination with other   requested Event Time Job Description Attributes in order to display   time attributes to a user.  The difference between this attribute and   the 'integer' value of a "time-at-xxx" attribute is the number ofHastings, et al.            Standards Track                   [Page 120]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   seconds ago that the "time-at-xxx" event occurred.  A client can   compute the wall-clock time at which the "time-at-xxx" event occurred   by subtracting this difference from the client's wall-clock time.4.3.14.5 date-time-at-creation (dateTime)   This attribute indicates the date and time at which the Job object   was created.4.3.14.6 date-time-at-processing (dateTime)   This attribute indicates the date and time at which the Job object   first began processing after the create operation or the most recent   Restart-Job operation.4.3.14.7 date-time-at-completed (dateTime)   This attribute indicates the date and time at which the Job object   completed (or was canceled or aborted).4.3.15 number-of-intervening-jobs (integer(0:MAX))   This attribute indicates the number of jobs that are "ahead" of this   job in the relative chronological order of expected time to complete   (i.e., the current scheduled order). For efficiency, it is only   necessary to calculate this value when an operation is performed that   requests this attribute.4.3.16 job-message-from-operator (text(127))   This attribute provides a message from an operator, system   administrator or "intelligent" process to indicate to the end user   the reasons for modification or other management action taken on a   job.4.3.17 Job Size Attributes   This sub-section defines job attributes that describe the size of the   job.  These attributes are not intended to be counters; they are   intended to be useful routing and scheduling information if known.   For these attributes, the Printer object may try to compute the value   if it is not supplied in the create request.  Even if the client does   supply a value for these three attributes in the create request, the   Printer object MAY choose to change the value if the Printer object   is able to compute a value which is more accurate than the client   supplied value.  The Printer object may be able to determine the   correct value for these attributes either right at job submission   time or at any later point in time.Hastings, et al.            Standards Track                   [Page 121]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.3.17.1 job-k-octets (integer(0:MAX))   This attribute specifies the total size of the document(s) in K   octets, i.e., in units of 1024 octets requested to be processed in   the job.  The value MUST be rounded up, so that a job between 1 and   1024 octets MUST be indicated as being 1, 1025 to 2048 MUST be 2,   etc.   This value MUST NOT include the multiplicative factors contributed by   the number of copies specified by the "copies" attribute, independent   of whether the device can process multiple copies without making   multiple passes over the job or document data and independent of   whether the output is collated or not.  Thus the value is independent   of the implementation and indicates the size of the document(s)   measured in K octets independent of the number of copies.   This value MUST also not include the multiplicative factor due to a   copies instruction embedded in the document data.  If the document   data actually includes replications of the document data, this value   will include such replication.  In other words, this value is always   the size of the source document data, rather than a measure of the   hardcopy output to be produced.4.3.17.2 job-impressions (integer(0:MAX))   This attribute specifies the total size in number of impressions of   the document(s) being submitted (see the definition of impression insection 12.2.5).   As with "job-k-octets", this value MUST NOT include the   multiplicative factors contributed by the number of copies specified   by the "copies" attribute, independent of whether the device can   process multiple copies without making multiple passes over the job   or document data and independent of whether the output is collated or   not.  Thus the value is independent of the implementation and   reflects the size of the document(s) measured in impressions   independent of the number of copies.   As with "job-k-octets", this value MUST also not include the   multiplicative factor due to a copies instruction embedded in the   document data.  If the document data actually includes replications   of the document data, this value will include such replication.  In   other words, this value is always the number of impressions in the   source document data, rather than a measure of the number of   impressions to be produced by the job.Hastings, et al.            Standards Track                   [Page 122]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.3.17.3 job-media-sheets (integer(0:MAX))   This attribute specifies the total number of media sheets to be   produced for this job.   Unlike the "job-k-octets" and the "job-impressions" attributes, this   value MUST include the multiplicative factors contributed by the   number of copies specified by the "copies" attribute and a 'number of   copies' instruction embedded in the document data, if any.  This   difference allows the system administrator to control the lower and   upper bounds of both (1) the size of the document(s) with "job-k-   octets-supported" and "job-impressions-supported" and (2) the size of   the job with "job-media-sheets-supported".4.3.18 Job Progress Attributes   This sub-section defines job attributes that describe the progress of   the job.  These attributes are intended to be counters.  That is, the   value for a job that has not started processing MUST be 0.  When the   job's "job-state" is 'processing' or 'processing-stopped', this value   is intended to contain the amount of the job that has been processed   to the time at which the attributes are requested.  When the job   enters the 'completed', 'canceled', or 'aborted' states, these values   are the final values for the job.4.3.18.1 job-k-octets-processed (integer(0:MAX))   This attribute specifies the total number of octets processed in K   octets, i.e., in units of 1024 octets so far.  The value MUST be   rounded up, so that a job between 1 and 1024 octets inclusive MUST be   indicated as being 1, 1025 to 2048 inclusive MUST be 2, etc.   For implementations where multiple copies are produced by the   interpreter with only a single pass over the data, the final value   MUST be equal to the value of the "job-k-octets" attribute.  For   implementations where multiple copies are produced by the interpreter   by processing the data for each copy, the final value MUST be a   multiple of the value of the "job-k-octets" attribute.4.3.18.2 job-impressions-completed (integer(0:MAX))   This job attribute specifies the number of impressions completed for   the job so far.  For printing devices, the impressions completed   includes interpreting, marking, and stacking the output.Hastings, et al.            Standards Track                   [Page 123]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.3.18.3 job-media-sheets-completed (integer(0:MAX))   This job attribute specifies the media-sheets completed marking and   stacking for the entire job so far whether those sheets have been   processed on one side or on both.4.3.19 attributes-charset (charset)   This REQUIRED attribute is populated using the value in the client   supplied "attributes-charset" attribute in the create request.  It   identifies the charset (coded character set and encoding method) used   by any Job attributes with attribute syntax 'text' and 'name' that   were supplied by the client in the create request.  SeeSection 3.1.4   for a complete description of the "attributes-charset" operation   attribute.   This attribute does not indicate the charset in which the 'text' and   'name' values are stored internally in the Job object.  The internal   charset is implementation-defined.  The IPP object MUST convert from   whatever the internal charset is to that being requested in an   operation as specified inSection 3.1.4.4.3.20 attributes-natural-language (naturalLanguage)   This REQUIRED attribute is populated using the value in the client   supplied "attributes-natural-language" attribute in the create   request.  It identifies the natural language used for any Job   attributes with attribute syntax 'text' and 'name' that were supplied   by the client in the create request.  SeeSection 3.1.4 for a   complete description of the "attributes-natural-language" operation   attribute.  See Sections4.1.1.2 and4.1.2.2 for how a Natural   Language Override may be supplied explicitly for each 'text' and   'name' attribute value that differs from the value identified by the   "attributes-natural-language" attribute.4.4 Printer Description Attributes   These attributes form the attribute group called "printer-   description".  The following table summarizes these attributes, their   syntax, and whether or not they are REQUIRED for a Printer object to   support.  If they are not indicated as REQUIRED, they are OPTIONAL.   The maximum size in octets for 'text' and 'name' attributes is   indicated in parenthesizes.   Note: How these attributes are set by an Administrator is outside the   scope of this IPP/1.1 document.Hastings, et al.            Standards Track                   [Page 124]

RFC 2911              IPP/1.1: Model and Semantics        September 2000  +----------------------------+---------------------------+-----------+  |      Attribute             |     Syntax                | REQUIRED? |  +----------------------------+---------------------------+-----------+  | printer-uri-supported      | 1setOf uri                |  REQUIRED |  +----------------------------+---------------------------+-----------+  | uri-security-supported     | 1setOf type2 keyword      |  REQUIRED |  +----------------------------+---------------------------+-----------+  | uri-authentication-        | 1setOf type2 keyword      |  REQUIRED |  |     supported              |                           |           |  +----------------------------+---------------------------+-----------+  | printer-name               | name (127)                |  REQUIRED |  +----------------------------+---------------------------+-----------+  | printer-location           | text (127)                |           |  +----------------------------+---------------------------+-----------+  | printer-info               | text (127)                |           |  +----------------------------+---------------------------+-----------+  | printer-more-info          | uri                       |           |  +----------------------------+---------------------------+-----------+  | printer-driver-installer   | uri                       |           |  +----------------------------+---------------------------+-----------+  | printer-make-and-model     | text (127)                |           |  +----------------------------+---------------------------+-----------+  | printer-more-info-         | uri                       |           |  | manufacturer               |                           |           |  +----------------------------+---------------------------+-----------+  | printer-state              | type1 enum                |  REQUIRED |  +----------------------------+---------------------------+-----------+  | printer-state-reasons      | 1setOf type2 keyword      |  REQUIRED |  +----------------------------+---------------------------+-----------+  | printer-state-message      | text (MAX)                |           |  +----------------------------+---------------------------+-----------+  | ipp-versions-supported     | 1setOf type2 keyword      |  REQUIRED |  +----------------------------+---------------------------+-----------+  | operations-supported       | 1setOf type2 enum         |  REQUIRED |  +----------------------------+---------------------------+-----------+  | multiple-document-jobs-    | boolean                   |           |  |     supported              |                           |           |  +----------------------------+---------------------------+-----------+  | charset-configured         | charset                   |  REQUIRED |  +----------------------------+---------------------------+-----------+  | charset-supported          | 1setOf charset            |  REQUIRED |  +----------------------------+---------------------------+-----------+  | natural-language-configured| naturalLanguage           |  REQUIRED |  +----------------------------+---------------------------+-----------+  | generated-natural-language-| 1setOf naturalLanguage    |  REQUIRED |  | supported                  |                           |           |  +----------------------------+---------------------------+-----------+  | document-format-default    | mimeMediaType             |  REQUIRED |Hastings, et al.            Standards Track                   [Page 125]

RFC 2911              IPP/1.1: Model and Semantics        September 2000  +----------------------------+---------------------------+-----------+  | document-format-supported  | 1setOf mimeMediaType      |  REQUIRED |  +----------------------------+---------------------------+-----------+  | printer-is-accepting-jobs  | boolean                   |  REQUIRED |  +----------------------------+---------------------------+-----------+  | queued-job-count           | integer (0:MAX)           |  REQUIRED |  +----------------------------+---------------------------+-----------+  | printer-message-from-      | text (127)                |           |  | operator                   |                           |           |  +----------------------------+---------------------------+-----------+  | color-supported            | boolean                   |           |  +----------------------------+---------------------------+-----------+  | reference-uri-schemes-     | 1setOf uriScheme          |           |  |   supported                |                           |           |  +----------------------------+---------------------------+-----------+  | pdl-override-supported     | type2 keyword             |  REQUIRED |  +----------------------------+---------------------------+-----------+  | printer-up-time            | integer (1:MAX)           |  REQUIRED |  +----------------------------+---------------------------+-----------+  | printer-current-time       | dateTime                  |           |  +----------------------------+---------------------------+-----------+  | multiple-operation-time-out| integer (1:MAX)           |           |  +----------------------------+---------------------------+-----------+  | compression-supported      | 1setOf type3 keyword      |  REQUIRED |  +----------------------------+---------------------------+-----------+  | job-k-octets-supported     | rangeOfInteger (0:MAX)    |           |  +----------------------------+---------------------------+-----------+  | job-impressions-supported  | rangeOfInteger (0:MAX)    |           |  +----------------------------+---------------------------+-----------+  | job-media-sheets-supported | rangeOfInteger (0:MAX)    |           |  +----------------------------+---------------------------+-----------+  | pages-per-minute           | integer(0:MAX)            |           |  +----------------------------+---------------------------+-----------+  | pages-per-minute-color     | integer(0:MAX)            |           |  +----------------------------+---------------------------+-----------+4.4.1 printer-uri-supported (1setOf uri)   This REQUIRED Printer attribute contains at least one URI for the   Printer object.  It OPTIONALLY contains more than one URI for the   Printer object.    An administrator determines a Printer object's   URI(s) and configures this attribute to contain those URIs by some   means outside the scope of this IPP/1.1 document.  The precise format   of this URI is implementation dependent and depends on the protocol.   See the next two sections for a description of the "uri-security-   supported" and "uri-authentication-supported" attributes, both ofHastings, et al.            Standards Track                   [Page 126]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   which are the REQUIRED companion attributes to this "printer-uri-   supported" attribute.  Seesection 2.4 on Printer object identity andsection 8.2 on security and URIs for more information.4.4.2 uri-authentication-supported (1setOf type2 keyword)   This REQUIRED Printer attribute MUST have the same cardinality   (contain the same number of values) as the "printer-uri-supported"   attribute.  This attribute identifies the Client Authentication   mechanism associated with each URI listed in the "printer-uri-   supported" attribute. The Printer object uses the specified mechanism   to identify the authenticated user (seesection 8.3).  The "i th"   value in "uri-authentication-supported" corresponds to the "i th"   value in "printer-uri-supported" and it describes the authentication   mechanisms used by the Printer when accessed via that URI.  See   [RFC2910] for more details on Client Authentication.   The following standard keyword values are defined:      'none': There is no authentication mechanism associated with the         URI.  The Printer object assumes that the authenticated user is         "anonymous".      'requesting-user-name': When a client performs an operation whose         target is the associated URI, the Printer object assumes that         the authenticated user is specified by the "requesting-user-         name" Operation attribute (seesection 8.3). If the         "requesting-user-name" attribute is absent in a request, the         Printer object assumes that the authenticated user is         "anonymous".      'basic': When a client performs an operation whose target is the         associated URI, the Printer object challenges the client with         HTTP basic authentication [RFC2617]. The Printer object assumes         that the authenticated user is the name received via the basic         authentication mechanism.      'digest': When a client performs an operation whose target is the         associated URI, the Printer object challenges the client with         HTTP digest authentication [RFC2617]. The Printer object         assumes that the authenticated user is the name received via         the digest authentication mechanism.      'certificate': When a client performs an operation whose target is         the associated URI, the Printer object expects the client to         provide a certificate. The Printer object assumes that the         authenticated user is the textual name contained within the         certificate.Hastings, et al.            Standards Track                   [Page 127]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.4.3 uri-security-supported (1setOf type2 keyword)   This REQUIRED Printer attribute MUST have the same cardinality   (contain the same number of values) as the "printer-uri-supported"   attribute.  This attribute identifies the security mechanisms used   for each URI listed in the "printer-uri-supported" attribute.  The "i   th" value in "uri-security-supported" corresponds to the "i th" value   in "printer-uri-supported" and it describes the security mechanisms   used for accessing the Printer object via that URI.  See [RFC2910]   for more details on security mechanisms.   The following standard keyword values are defined:      'none': There are no secure communication channel protocols in use         for the given URI.      'ssl3': SSL3 [SSL] is the secure communications channel protocol         in use for the given URI.      'tls':  TLS [RFC2246] is the secure communications channel         protocol in use for the given URI.   This attribute is orthogonal to the definition of a Client   Authentication mechanism.  Specifically, 'none' does not exclude   Client Authentication. Seesection 4.4.2.   Consider the following example.  For a single Printer object, an   administrator configures the "printer-uri-supported",  "uri-   authentication-supported" and "uri-security-supported" attributes as   follows:     "printer-uri-supported": 'xxx://acme.com/open-use-printer',        'xxx://acme.com/restricted-use-printer',        'xxx://acme.com/private-printer'     "uri-authentication-supported": 'none', 'digest', 'basic'     "uri-security-supported": 'none', 'none', 'tls'   Note:  'xxx'  is not a valid scheme.  See the IPP/1.1 "Transport and   Encoding" document [RFC2910] for the actual URI schemes to be used in   object target attributes.   In this case, one Printer object has three URIs.      - For the first URI, 'xxx://acme.com/open-use-printer', the value        'none' in "uri-security-supported" indicates that there is no        secure channel protocol configured to run under HTTP.  The value        of 'none' in "uri-authentication-supported" indicates that all        users are 'anonymous'.  There will be no challenge and the        Printer will ignore "requesting-user-name".Hastings, et al.            Standards Track                   [Page 128]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      - For the second URI, 'xxx://acme.com/restricted-use-printer', the        value 'none' in "uri-security-supported" indicates that there is        no secure channel protocol configured to run under HTTP. The        value of 'digest' in "uri-authentication-supported" indicates        that the Printer will issue a challenge and that the Printer        will use the name supplied by the digest mechanism to determine        the authenticated user (seesection 8.3).      - For the third URI, 'xxx://acme.com/private-printer', the value        'tls' in "uri-security-supported" indicates that TLS is being        used to secure the channel.  The client SHOULD be prepared to        use TLS framing to negotiate an acceptable ciphersuite to use        while communicating with the Printer object.  In this case, the        name implies the use of a secure communications channel, but the        fact is made explicit by the presence of the 'tls' value in        "uri-security-supported".  The client does not need to resort to        understanding which security it must use by following naming        conventions or by parsing the URI to determine which security        mechanisms are implied.  The value of 'basic' in "uri-        authentication-supported" indicates that the Printer will issue        a challenge and that the Printer will use the name supplied by        the digest mechanism to determine the authenticated user (seesection 8.3).  Because this challenge occurs in a tls session,        the channel is secure.   It is expected that many IPP Printer objects will be configured to   support only one channel (either configured to use TLS access or not)   and only one authentication mechanism. Such Printer objects only have   one URI listed in the "printer-uri-supported" attribute.  No matter   the configuration of the Printer object (whether it has only one URI   or more than one URI), a client MUST supply only one URI in the   target "printer-uri" operation attribute.4.4.4 printer-name (name(127))   This REQUIRED Printer attribute contains the name of the Printer   object.  It is a name that is more end-user friendly than a URI. An   administrator determines a printer's name and sets this attribute to   that name. This name may be the last part of the printer's URI or it   may be unrelated.  In non-US-English locales, a name may contain   characters that are not allowed in a URI.4.4.5 printer-location (text(127))   This Printer attribute identifies the location of the device. This   could include things like: "in Room 123A, second floor of building   XYZ".Hastings, et al.            Standards Track                   [Page 129]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.4.6 printer-info (text(127))   This Printer attribute identifies the descriptive information about   this Printer object.  This could include things like: "This printer   can be used for printing color transparencies for HR presentations",   or "Out of courtesy for others, please print only small (1-5 page)   jobs at this printer", or even "This printer is going away on July 1,   1997, please find a new printer".4.4.7 printer-more-info (uri)   This Printer attribute contains a URI used to obtain more information   about this specific Printer object.  For example, this could be an   HTTP type URI referencing an HTML page accessible to a Web Browser.   The information obtained from this URI is intended for end user   consumption.  Features outside the scope of IPP can be accessed from   this URI.  The information is intended to be specific to this printer   instance and site specific services (e.g. job pricing, services   offered, end user assistance). The device manufacturer may initially   populate this attribute.4.4.8 printer-driver-installer (uri)   This Printer attribute contains a URI to use to locate the driver   installer for this Printer object.   This attribute is intended for   consumption by automata.  The mechanics of print driver installation   is outside the scope of this IPP/1.1 document.  The device   manufacturer may initially populate this attribute.4.4.9 printer-make-and-model (text(127))   This Printer attribute identifies the make and model of the device.   The device manufacturer may initially populate this attribute.4.4.10 printer-more-info-manufacturer (uri)   This Printer attribute contains a URI used to obtain more information   about this type of device.  The information obtained from this URI is   intended for end user consumption.  Features outside the scope of IPP   can be accessed from this URI (e.g., latest firmware, upgrades, print   drivers, optional features available, details on color support).  The   information is intended to be germane to this printer without regard   to site specific modifications or services. The device manufacturer   may initially populate this attribute.Hastings, et al.            Standards Track                   [Page 130]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.4.11 printer-state (type1 enum)   This REQUIRED Printer attribute identifies the current state of the   device.  The "printer-state reasons" attribute augments the   "printer-state" attribute to give more detailed information about the   Printer in the given printer state.   A Printer object need only update this attribute before responding to   an operation which requests the attribute; the Printer object NEED   NOT update this attribute continually, since asynchronous event   notification is not part of IPP/1.1.  A Printer NEED NOT implement   all values if they are not applicable to a given implementation.   The following standard enum values are defined:   Value  Symbolic Name and Description   '3'    'idle':  Indicates that new jobs can start processing without                waiting.   '4'    'processing':  Indicates that jobs are processing; new jobs                will wait before processing.   '5'    'stopped':  Indicates that no jobs can be processed and                intervention is required.   Values of "printer-state-reasons", such as 'spool-area-full' and   'stopped-partly', MAY be used to provide further information.4.4.12 printer-state-reasons (1setOf type2 keyword)   This REQUIRED Printer attribute supplies additional detail about the   device's state.  Some of the these value definitions indicate   conformance requirements; the rest are OPTIONAL.   Each keyword value MAY have a suffix to indicate its level of   severity.  The three levels are: report (least severe), warning, and   error (most severe).      - '-report':  This suffix indicates that the reason is a "report".        An implementation may choose to omit some or all reports. Some        reports specify finer granularity about the printer state;        others serve as a precursor to a warning. A report MUST contain        nothing that could affect the printed output.      - '-warning': This suffix indicates that the reason is a        "warning".  An implementation may choose to omit some or all        warnings. Warnings serve as a precursor to an error. A warning        MUST contain nothing that prevents a job from completing, though        in some cases the output may be of lower quality.Hastings, et al.            Standards Track                   [Page 131]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      - '-error': This suffix indicates that the reason is an "error".        An implementation MUST include all errors. If this attribute        contains one or more errors, printer MUST be in the stopped        state.   If the implementation does not add any one of the three suffixes, all   parties MUST assume that the reason is an "error".   If a Printer object controls more than one output device, each value   of this attribute MAY apply to one or more of the output devices.  An   error on one output device that does not stop the Printer object as a   whole MAY appear as a warning in the Printer's "printer-state-reasons   attribute".  If the "printer-state" for such a Printer has a value of   'stopped', then there MUST be an error reason among the values in the   "printer-state-reasons" attribute.   The following standard keyword values are defined:      'other': The device has detected an error other than one listed in         this document.      'none': There are not reasons. This state reason is semantically         equivalent to "printer-state-reasons" without any value and         MUST be used, since the 1setOf attribute syntax requires at         least one value.      'media-needed': A tray has run out of media.      'media-jam': The device has a media jam.      'moving-to-paused':  Someone has paused the Printer object using         the Pause-Printer operation (seesection 3.2.7) or other means,         but the device(s) are taking an appreciable time to stop.         Later, when all output has stopped, the "printer-state" becomes         'stopped', and the 'paused' value replaces the 'moving-to-         paused' value in the "printer-state-reasons" attribute.  This         value MUST be supported, if the Pause-Printer operation is         supported and the implementation takes significant time to         pause a device in certain circumstances.      'paused': Someone has paused the Printer object using the Pause-         Printer operation (seesection 3.2.7) or other means and the         Printer object's "printer-state" is 'stopped'.  In this state,         a Printer MUST NOT produce printed output, but it MUST perform         other operations requested by a client.  If a Printer had been         printing a job when the Printer was paused, the Printer MUST         resume printing that job when the Printer is no longer paused         and leave no evidence in the printed output of such a pause.         This value MUST be supported, if the Pause-Printer operation is         supported.      'shutdown': Someone has removed a Printer object from service, and         the device may be powered down or physically removed.  In this         state, a Printer object MUST NOT produce printed output, andHastings, et al.            Standards Track                   [Page 132]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         unless the Printer object is realized by a print server that is         still active, the Printer object MUST perform no other         operations requested by a client, including returning this         value. If a Printer object had been printing a job when it was         shutdown, the Printer NEED NOT resume printing that job when         the Printer is no longer shutdown. If the Printer resumes         printing such a job, it may leave evidence in the printed         output of such a shutdown, e.g. the part printed before the         shutdown may be printed a second time after the shutdown.      'connecting-to-device': The Printer object has scheduled a job on         the output device and is in the process of connecting to a         shared network output device (and might not be able to actually         start printing the job for an arbitrarily long time depending         on the usage of the output device by other servers on the         network).      'timed-out': The server was able to connect to the output device         (or is always connected), but was unable to get a response from         the output device.      'stopping': The Printer object is in the process of stopping the         device and will be stopped in a while. When the device is         stopped, the Printer object will change the Printer object's         state to 'stopped'.  The 'stopping-warning' reason is never an         error, even for a Printer with a single output device.  When an         output-device ceases accepting jobs, the Printer will have this         reason while the output device completes printing.      'stopped-partly': When a Printer object controls more than one         output device, this reason indicates that one or more output         devices are stopped.  If the reason is a report, fewer than         half of the output devices are stopped.  If the reason is a         warning, fewer than all of the output devices are stopped.      'toner-low': The device is low on toner.      'toner-empty':  The device is out of toner.      'spool-area-full': The limit of persistent storage allocated for         spooling has been reached.  The Printer is temporarily unable         to accept more jobs.  The Printer will remove this value when         it is able to accept more jobs.  This value SHOULD be used by a         non-spooling Printer that only accepts one or a small number         jobs at a time or a spooling Printer that has filled the spool         space.      'cover-open': One or more covers on the device are open.      'interlock-open': One or more interlock devices on the printer are         unlocked.      'door-open': One or more doors on the device are open.      'input-tray-missing': One or more input trays are not in the         device.      'media-low': At least one input tray is low on media.      'media-empty': At least one input tray is empty.Hastings, et al.            Standards Track                   [Page 133]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      'output-tray-missing': One or more output trays are not in the         device      'output-area-almost-full': One or more output area is almost full         (e.g. tray, stacker, collator).      'output-area-full': One or more output area is full. (e.g. tray,         stacker, collator)      'marker-supply-low': The device is low on at least one marker         supply.  (e.g. toner, ink, ribbon)      'marker-supply-empty: The device is out of at least one marker         supply. (e.g. toner, ink, ribbon)      'marker-waste-almost-full': The device marker supply waste         receptacle is almost full.      'marker-waste-full': The device marker supply waste receptacle is         full.      'fuser-over-temp': The fuser temperature is above normal.      'fuser-under-temp': The fuser temperature is below normal.      'opc-near-eol': The optical photo conductor is near end of life.      'opc-life-over': The optical photo conductor is no longer         functioning.      'developer-low': The device is low on developer.      'developer-empty: The device is out of developer.      'interpreter-resource-unavailable': An interpreter resource is         unavailable (i.e. font, form)4.4.13 printer-state-message (text(MAX))   This Printer attribute specifies information about the "printer-   state" and "printer-state-reasons" attributes in human readable text.   If the Printer object supports this attribute, the Printer object   MUST be able to generate this message in any of the natural languages   identified by the Printer's "generated-natural-language-supported"   attribute (see the "attributes-natural-language" operation attribute   specified inSection 3.1.4.1).4.4.14 ipp-versions-supported (1setOf type2 keyword)   This REQUIRED attribute identifies the IPP protocol version(s) that   this Printer supports, including major and minor versions, i.e., the   version numbers for which this Printer implementation meets the   conformance requirements.  For version number validation, the Printer   matches the (two-octet binary) "version-number" parameter supplied by   the client in each request (see sections3.1.1 and3.1.8) with the   (US-ASCII) keyword values of this attribute.Hastings, et al.            Standards Track                   [Page 134]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The following standard keyword values are defined:      '1.0': Meets the conformance requirement of IPP version 1.0 as         specified inRFC 2566 [RFC2566] andRFC 2565 [RFC2565]         including any extensions registered according toSection 6 and         any extension defined in this version or any future version of         the IPP "Model and Semantics" document or the IPP "Encoding and         Transport" document following the rules, if any, when the         "version-number" parameter is '1.0'.      '1.1': Meets the conformance requirement of IPP version 1.1 as         specified in this document and [RFC2910] including any         extensions registered according toSection 6 and any extension         defined in any future versions of the IPP "Model and Semantics"         document or the IPP Encoding and Transport document following         the rules, if any, when the "version-number" parameter is         '1.1'.4.4.15 operations-supported (1setOf type2 enum)   This REQUIRED Printer attribute specifies the set of supported   operations for this Printer object and contained Job objects.   This attribute is encoded as any other enum attribute syntax   according to [RFC2910] as 32-bits.  However, all 32-bit enum values   for this attribute MUST NOT exceed 0x00008FFF, since these same   values are also passed in two octets in the "operation-id" parameter   (seesection 3.1.1) in each Protocol request with the two high order   octets omitted in order to indicate the operation being performed   [RFC2910].   The following standard enum and "operation-id" (seesection 3.1.2)   values are defined:Hastings, et al.            Standards Track                   [Page 135]

RFC 2911              IPP/1.1: Model and Semantics        September 2000     Value               Operation Name     -----------------   -------------------------------------     0x0000              reserved, not used     0x0001              reserved, not used     0x0002              Print-Job     0x0003              Print-URI     0x0004              Validate-Job     0x0005              Create-Job     0x0006              Send-Document     0x0007              Send-URI     0x0008              Cancel-Job     0x0009              Get-Job-Attributes     0x000A              Get-Jobs     0x000B              Get-Printer-Attributes     0x000C              Hold-Job     0x000D              Release-Job     0x000E              Restart-Job     0x000F              reserved for a future operation     0x0010              Pause-Printer     0x0011              Resume-Printer     0x0012              Purge-Jobs     0x0013-0x3FFF       reserved for future IETF standards track                         operations (seesection 6.4)     0x4000-0x8FFF       reserved for vendor extensions (seesection 6.4)4.4.16 multiple-document-jobs-supported (boolean)   This Printer attribute indicates whether or not the Printer supports   more than one document per job, i.e., more than one Send-Document or   Send-Data operation with document data.  If the Printer supports the   Create-Job and Send-Document operations (seesection 3.2.4 and   3.3.1), it MUST support this attribute.4.4.17 charset-configured (charset)   This REQUIRED Printer attribute identifies the charset that the   Printer object has been configured to represent 'text' and 'name'   Printer attributes that are set by the operator, system   administrator, or manufacturer, i.e., for "printer-name" (name),   "printer-location" (text), "printer-info" (text), and "printer-make-   and-model" (text).  Therefore, the value of the Printer object's   "charset-configured" attribute MUST also be among the values of the   Printer object's "charset-supported" attribute.Hastings, et al.            Standards Track                   [Page 136]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.4.18 charset-supported (1setOf charset)   This REQUIRED Printer attribute identifies the set of charsets that   the Printer and contained Job objects support in attributes with   attribute syntax 'text' and 'name'. At least the value 'utf-8' MUST   be present, since IPP objects MUST support the UTF-8 [RFC2279]   charset.  If a Printer object supports a charset, it means that for   all attributes of syntax 'text' and 'name' the IPP object MUST (1)   accept the charset in requests and return the charset in responses as   needed.   If more charsets than UTF-8 are supported, the IPP object MUST   perform charset conversion between the charsets as described inSection 3.1.4.2.4.4.19 natural-language-configured (naturalLanguage)   This REQUIRED Printer attribute identifies the natural language that   the Printer object has been configured to represent 'text' and 'name'   Printer attributes that are set by the operator, system   administrator, or manufacturer, i.e., for "printer-name" (name),   "printer-location" (text), "printer-info" (text), and "printer-make-   and-model" (text).  When returning these Printer attributes, the   Printer object MAY return them in the configured natural language   specified by this attribute, instead of the natural language   requested by the client in the "attributes-natural-language"   operation attribute.  SeeSection 3.1.4.1 for the specification of   the OPTIONAL multiple natural language support.  Therefore, the value   of the Printer object's "natural-language-configured" attribute MUST   also be among the values of the Printer object's "generated-natural-   language-supported" attribute.4.4.20 generated-natural-language-supported (1setOf naturalLanguage)   This REQUIRED Printer attribute identifies the natural language(s)   that the Printer object and contained Job objects support in   attributes with attribute syntax 'text' and 'name'.  The natural   language(s) supported depends on implementation and/or configuration.   Unlike charsets, IPP objects MUST accept requests with any natural   language or any Natural Language Override whether the natural   language is supported or not.   If a Printer object supports a natural language, it means that for   any of the attributes for which the Printer or Job object generates   messages, i.e., for the "job-state-message" and "printer-state-   message" attributes and Operation Messages (seeSection 3.1.5) in   operation responses, the Printer and Job objects MUST be able toHastings, et al.            Standards Track                   [Page 137]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   generate messages in any of the Printer's supported natural   languages.  Seesection 3.1.4 for the definition of 'text' and 'name'   attributes in operation requests and responses.   Note: A Printer object that supports multiple natural languages,   often has separate catalogs of messages, one for each natural   language supported.4.4.21 document-format-default (mimeMediaType)   This REQUIRED Printer attribute identifies the document format that   the Printer object has been configured to assume if the client does   not supply a "document-format" operation attribute in any of the   operation requests that supply document data.  The standard values   for this attribute are Internet Media types (sometimes called MIME   types).  For further details see the description of the   'mimeMediaType' attribute syntax inSection 4.1.9.4.4.22 document-format-supported (1setOf mimeMediaType)   This REQUIRED Printer attribute identifies the set of document   formats that the Printer object and contained Job objects can   support. For further details see the description of the   'mimeMediaType' attribute syntax inSection 4.1.9.4.4.23 printer-is-accepting-jobs (boolean)   This REQUIRED Printer attribute indicates whether the printer is   currently able to accept jobs, i.e., is accepting Print-Job, Print-   URI, and Create-Job requests.  If the value is 'true', the printer is   accepting jobs.  If the value is 'false', the Printer object is   currently rejecting any jobs submitted to it.  In this case, the   Printer object returns the 'server-error-not-accepting-jobs' status   code.   This value is independent of the "printer-state" and "printer-state-   reasons" attributes because its value does not affect the current   job; rather it affects future jobs.  This attribute, when 'false',   causes the Printer to reject jobs even when the "printer-state" is   'idle' or, when 'true', causes the Printer object to accepts jobs   even when the "printer-state" is 'stopped'.4.4.24 queued-job-count (integer(0:MAX))   This REQUIRED Printer attribute contains a count of the number of   jobs that are either 'pending', 'processing', 'pending-held', or   'processing-stopped' and is set by the Printer object.Hastings, et al.            Standards Track                   [Page 138]

RFC 2911              IPP/1.1: Model and Semantics        September 20004.4.25 printer-message-from-operator (text(127))   This Printer attribute provides a message from an operator, system   administrator or "intelligent" process to indicate to the end user   information or status of the printer, such as why it is unavailable   or when it is expected to be available.4.4.26 color-supported (boolean)   This Printer attribute identifies whether the device is capable of   any type of color printing at all, including highlight color.  All   document instructions having to do with color are embedded within the   document PDL (none are external IPP attributes in IPP/1.1).   Note:  end-users are able to determine the nature and details of the   color support by querying the "printer-more-info-manufacturer"   Printer attribute.4.4.27 reference-uri-schemes-supported (1setOf uriScheme)   This Printer attribute specifies which URI schemes are supported for   use in the "document-uri" operation attribute of the Print-URI or   Send-URI operation.  If a Printer object supports these optional   operations, it MUST support the "reference-uri-schemes-supported"   Printer attribute with at least the following schemed URI value:      'ftp':  The Printer object will use an FTP 'get' operation as         defined inRFC 2228 [RFC2228] using FTP URLs as defined by         [RFC2396] and [RFC2316].   The Printer object MAY OPTIONALLY support other URI schemes (seesection 4.1.6).4.4.28 pdl-override-supported (type2 keyword)   This REQUIRED Printer attribute expresses the ability for a   particular Printer implementation to either attempt to override   document data instructions with IPP attributes or not.   This attribute takes on the following keyword values:      - 'attempted': This value indicates that the Printer object         attempts to make the IPP attribute values take precedence over         embedded instructions in the document data, however there is no         guarantee.      - 'not-attempted': This value indicates that the Printer object         makes no attempt to make the IPP attribute values take         precedence over embedded instructions in the document data.Hastings, et al.            Standards Track                   [Page 139]

RFC 2911              IPP/1.1: Model and Semantics        September 2000Section 15 contains a full description of how this attribute   interacts with and affects other IPP attributes, especially the   "ipp-attribute-fidelity" attribute.4.4.29 printer-up-time (integer(1:MAX))   This REQUIRED Printer attribute indicates the amount of time (in   seconds) that this Printer instance has been up and running.  The   value is a monotonically increasing value starting from 1 when the   Printer object is started-up (initialized, booted, etc.).  This value   is used to populate the Event Time Job Description Job attributes   "time-at-creation", "time-at-processing", and "time-at-completed"   (seesection 4.3.14).   If the Printer object goes down at some value 'n', and comes back up,   the implementation MAY:      1. Know how long it has been down, and resume at some value         greater than 'n', or      2. Restart from 1.   In other words, if the device or devices that the Printer object is   representing are restarted or power cycled, the Printer object MAY   continue counting this value or MAY reset this value to 1 depending   on implementation.  However, if the Printer object software ceases   running, and restarts without knowing the last value for "printer-   up-time", the implementation MUST reset this value to 1.  If this   value is reset and the Printer has persistent jobs, the Printer MUST   reset the "time-at-xxx(integer) Event Time Job Description attributes   according toSection 4.3.14.  An implementation MAY use both   implementation alternatives, depending on warm versus cold start,   respectively.4.4.30 printer-current-time (dateTime)   This Printer attribute indicates the current date and time.  This   value is used to populate the Event Time Job Description attributes:   "date-time-at-creation", "date-time-at-processing", and "date-time-   at-completed" (seeSection 4.3.14).   The date and time is obtained on a "best efforts basis" and does not   have to be that precise in order to work in practice.  A Printer   implementation sets the value of this attribute by obtaining the date   and time via some implementation-dependent means, such as getting the   value from a network time server, initialization at time of   manufacture, or setting by an administrator.  See [IPP-IIG] for   examples.  If an implementation supports this attribute and the   implementation knows that it has not yet been set, then theHastings, et al.            Standards Track                   [Page 140]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   implementation MUST return the value of this attribute using the   out-of-band 'no-value' meaning not configured.  See the beginning ofsection 4.1.   The time zone of this attribute NEED NOT be the time zone used by   people located near the Printer object or device.  The client MUST   NOT expect that the time zone of any received 'dateTime' value to be   in the time zone of the client or in the time zone of the people   located near the printer.   The client SHOULD display any dateTime attributes to the user in   client local time by converting the 'dateTime' value returned by the   server to the time zone of the client, rather than using the time   zone returned by the Printer in attributes that use the 'dateTime'   attribute syntax.4.4.31 multiple-operation-time-out (integer(1:MAX))   This Printer attributes identifies the minimum time (in seconds) that   the Printer object waits for additional Send-Document or Send-URI   operations to follow a still-open Job object before taking  any   recovery actions, such as the ones indicated insection 3.3.1.  If   the Printer object supports the Create-Job and Send-Document   operations (seesection 3.2.4 and 3.3.1), it MUST support this   attribute.   It is RECOMMENDED that vendors supply a value for this attribute that   is between 60 and 240 seconds.  An implementation MAY allow a system   administrator to set this attribute (by means outside this IPP/1.1   document).  If so, the system administrator MAY be able to set values   outside this range.4.4.32 compression-supported (1setOf type3 keyword)   This REQUIRED Printer attribute identifies the set of supported   compression algorithms for document data.  Compression only applies   to the document data; compression does not apply to the encoding of   the IPP operation itself.  The supported values are used to validate   the client supplied "compression" operation attributes in Print-Job,   Send-Document, and Send-URI requests.   Standard keyword values are :   'none': no compression is used.   'deflate':  ZIP public domain inflate/deflate) compression technology      inRFC 1951 [RFC1951]   'gzip' GNU zip compression technology described inRFC 1952      [RFC1952].Hastings, et al.            Standards Track                   [Page 141]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   'compress': UNIX compression technology inRFC 1977 [RFC1977]4.4.33 job-k-octets-supported (rangeOfInteger(0:MAX))   This Printer attribute specifies the upper and lower bounds of total   sizes of jobs in K octets, i.e., in units of 1024 octets. The   supported values are used to validate the client supplied "job-k-   octets" operation attributes in create requests.  The corresponding   job description attribute "job-k-octets" is defined insection4.3.17.1.4.4.34 job-impressions-supported (rangeOfInteger(0:MAX))   This Printer attribute specifies the upper and lower bounds for the   number of impressions per job. The supported values are used to   validate the client supplied "job-impressions" operation attributes   in create requests.  The corresponding job description attribute   "job-impressions" is defined insection 4.3.17.2.4.4.35 job-media-sheets-supported (rangeOfInteger(0:MAX))   This Printer attribute specifies the upper and lower bounds for the   number of media sheets per job. The supported values are used to   validate the client supplied "job-media-sheets" operation attributes   in create requests.  The corresponding Job attribute "job-media-   sheets" is defined insection 4.3.17.3.4.4.36 pages-per-minute (integer(0:MAX))   This Printer attributes specifies the nominal number of pages per   minute to the nearest whole number which may be generated by this   printer (e.g., simplex, black-and-white).  This attribute is   informative, not a service guarantee.  Generally, it is the value   used in the marketing literature to describe the device.   A value of 0 indicates a device that takes more than two minutes to   process a page.4.4.37 pages-per-minute-color (integer(0:MAX))   This Printer attributes specifies the nominal number of pages per   minute to the nearest whole number which may be generated by this   printer when printing color (e.g., simplex, color).  For purposes of   this attribute, "color" means the same as for the "color-supported"   attribute, namely, the device is capable of any type of color   printing at all, including highlight color.  This attribute isHastings, et al.            Standards Track                   [Page 142]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   informative, not a service guarantee.  Generally, it is the value   used in the marketing literature to describe the color capabilities   of this device.   A value of 0 indicates a device that takes more than two minutes to   process a page.   If a color device has several color modes, it MAY use the pages-per-   minute value for this attribute that corresponds to the mode that   produces the highest number.   Black and white only printers MUST NOT support this attribute.  If   this attribute is present, then the "color-supported" Printer   description attribute MUST be present and have a 'true' value.   The values of these two attributes returned by the Get-Printer-   Attributes operation MAY be affected by the "document-format"   attribute supplied by the client in the Get-Printer-Attributes   request.  In other words, the implementation MAY have different   speeds depending on the document format being processed.  Seesection3.2.5.1 Get-Printer-Attributes.5. Conformance   This section describes conformance issues and requirements. This   document introduces model entities such as objects, operations,   attributes, attribute syntaxes, and attribute values.  These   conformance sections describe the conformance requirements which   apply to these model entities.5.1 Client Conformance Requirements   This section describes the conformance requirements for a client (seesection 2.1), whether it be:      1. contained within software controlled by an end user, e.g.         activated by the "Print" menu item in an application that sends         IPP requests or      2. the print server component that sends IPP requests to either an         output device or another "downstream" print server.   A conforming client MUST support all REQUIRED operations as defined   in this document.  For each attribute included in an operation   request, a conforming client MUST supply a value whose type and value   syntax conforms to the requirements of the Model document as   specified in Sections3 and4.  A conforming client MAY supply anyHastings, et al.            Standards Track                   [Page 143]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   IETF standards track extensions and/or vendor extensions in an   operation request, as long as the extensions meet the requirements inSection 6.   Otherwise, there are no conformance requirements placed on the user   interfaces provided by IPP clients or their applications.  For   example, one application might not allow an end user to submit   multiple documents per job, while another does.  One application   might first query a Printer object in order to supply a graphical   user interface (GUI) dialogue box with supported and default values   whereas a different implementation might not.   When sending a request, an IPP client NEED NOT supply any attributes   that are indicated as OPTIONALLY supplied by the client.   A client MUST be able to accept any of the attribute syntaxes defined   inSection 4.1, including their full range, that may be returned to   it in a response from a Printer object.  In particular for each   attribute that the client supports whose attribute syntax is 'text',   the client MUST accept and process both the 'textWithoutLanguage' and   'textWithLanguage' forms.  Similarly, for each attribute that the   client supports whose attribute syntax is 'name', the client MUST   accept and process both the 'nameWithoutLanguage' and   'nameWithLanguage' forms.  For presentation purposes, truncation of   long attribute values is not recommended.  A recommended approach   would be for the client implementation to allow the user to scroll   through long attribute values.   A response MAY contain attribute groups, attributes, attribute   syntaxes, values, and status codes that the client does not expect.   Therefore, a client implementation MUST gracefully handle such   responses and not refuse to inter-operate with a conforming Printer   that is returning IETF standards track extension or vendor   extensions, including attribute groups, attributes, attribute   syntaxes, attribute values, status codes, and out-of-band attribute   values that conform toSection 6.  Clients may choose to ignore any   parameters, attribute groups, attributes, attribute syntaxes, or   values that they do not understand.   While a client is sending data to a printer, it SHOULD do its best to   prevent a channel from being closed by a lower layer when the channel   is blocked (i.e. flow-controlled off) for whatever reason, e.g. 'out   of paper' or 'job ahead hasn't freed up enough memory'.  However, the   layer that launched the print submission (e.g. an end user) MAY close   the channel in order to cancel the job.  When a client closes a   channel, a Printer MAY print all or part of the received portion of   the document.  See the "Encoding and Transport" document [RFC2910]   for more details.Hastings, et al.            Standards Track                   [Page 144]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   A client MUST support Client Authentication as defined in the IPP/1.1   Encoding and Transport document [RFC2910].  A client SHOULD support   Operation Privacy and Server Authentication as defined in the IPP/1.1   Encoding and Transport document [RFC2910].  See alsosection 8 of   this document.5.2 IPP Object Conformance Requirements   This section specifies the conformance requirements for conforming   implementations of IPP objects (seesection 2).  These requirements   apply to an IPP object whether it is:      (1) an (embedded) device component that accepts IPP requests and      controls the device or      (2) a component of a print server that accepts IPP requests (where      the print server control one or more networked devices using IPP or      other protocols).5.2.1 Objects   Conforming implementations MUST implement all of the model objects as   defined in this document in the indicated sections:Section 2.1 - Printer ObjectSection 2.2 - Job Object5.2.2 Operations   Conforming IPP object implementations MUST implement all of the   REQUIRED model operations, including REQUIRED responses, as defined   in this document in the indicated sections:      For a Printer object:         Print-Job (section 3.2.1)               REQUIRED         Print-URI (section 3.2.2)               OPTIONAL         Validate-Job (section 3.2.3)            REQUIRED         Create-Job (section 3.2.4)              OPTIONAL         Get-Printer-Attributes (section 3.2.5)  REQUIRED         Get-Jobs (section 3.2.6)                REQUIRED         Pause-Printer (section 3.2.7)           OPTIONAL         Resume-Printer (section 3.2.8)          OPTIONAL         Purge-Jobs (section 3.2.9)              OPTIONALHastings, et al.            Standards Track                   [Page 145]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      For a Job object:         Send-Document (section 3.3.1)           OPTIONAL         Send-URI (section 3.3.2)                OPTIONAL         Cancel-Job (section 3.3.3)              REQUIRED         Get-Job-Attributes (section 3.3.4)      REQUIRED         Hold-Job (section 3.3.5)                OPTIONAL         Release-Job (section 3.3.6)             OPTIONAL         Restart-Job (section 3.3.7)             OPTIONAL   Conforming IPP objects MUST support all REQUIRED operation attributes   and all values of such attributes if so indicated in the description.   Conforming IPP objects MUST ignore all unsupported or unknown   operation attributes or operation attribute groups received in a   request, but MUST reject a request that contains a supported   operation attribute that contains an unsupported value.   Conforming IPP objects MAY return operation responses that contain   attributes groups, attributes names,  attribute syntaxes, attribute   values, and status codes that are extensions to this standard.  The   additional attribute groups MAY occur in any order.   The following section on object attributes specifies the support   required for object attributes.5.2.3 IPP Object Attributes   Conforming IPP objects MUST support all of the REQUIRED object   attributes, as defined in this document in the indicated sections.   If an object supports an attribute, it MUST support only those values   specified in this document or through the extension mechanism   described insection 5.2.4. It MAY support any non-empty subset of   these values.  That is, it MUST support at least one of the specified   values and at most all of them.5.2.4 Versions   IPP/1.1 clients MUST meet the conformance requirements for clients   specified in this document and [RFC2910].  IPP/1.1 clients MUST send   requests containing a "version-number" parameter with a '1.1' value.   IPP/1.1 Printer and Job objects MUST meet the conformance   requirements for IPP objects specified in this document and   [RFC2910].   IPP/1.1 objects MUST accept requests containing a   "version-number" parameter with a '1.1' value (or reject the request   if the operation is not supported).Hastings, et al.            Standards Track                   [Page 146]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   It is beyond the scope of this specification to mandate conformance   with previous versions.  IPP/1.1 was deliberately designed, however,   to make supporting previous versions easy.  It is worth noting that,   at the time of composing this specification (1999), we would expect   IPP/1.1 Printer implementations to:     understand any valid request in the format of IPP/1.0, or 1.1;     respond appropriately with a response containing the same     "version-number" parameter value used by the client in the request.   And we would expect IPP/1.1 clients to:     understand any valid response in the format of IPP/1.0, or 1.1.   It is recommended that IPP/1.1 clients try supplying alternate   version numbers if they receive a 'server-error-version-not-   supported' error return in a response.5.2.5 Extensions   A conforming IPP object MAY support IETF standards track extensions   and vendor extensions, as long as the extensions meet the   requirements specified inSection 6.   For each attribute included in an operation response, a conforming   IPP object MUST return a value whose type and value syntax conforms   to the requirement of the Model document as specified in Sections3   and 4.5.2.6 Attribute Syntaxes   An IPP object MUST be able to accept any of the attribute syntaxes   defined inSection 4.1, including their full range, in any operation   in which a client may supply attributes or the system administrator   may configure attributes (by means outside the scope of this IPP/1.1   document).  In particular for each attribute that the IPP object   supports whose attribute syntax is 'text', the IPP object MUST accept   and process both the 'textWithoutLanguage' and 'textWithLanguage'   forms.  Similarly, for each attribute that the IPP object supports   whose attribute syntax is 'name', the IPP object MUST accept and   process both the 'nameWithoutLanguage' and 'nameWithLanguage' forms.   Furthermore, an IPP object MUST return attributes to the client in   operation responses that conform to the syntax specified inSection4.1, including their full range if supplied previously by a client.Hastings, et al.            Standards Track                   [Page 147]

RFC 2911              IPP/1.1: Model and Semantics        September 20005.2.7 Security   An IPP Printer implementation SHOULD contain support for Client   Authentication as defined in the IPP/1.1 Encoding and Transport   document [RFC2910].  A Printer implementation MAY allow an   administrator to configure the Printer so that all, some, or none of   the users are authenticated.  See alsosection 8 of this document.   An IPP Printer implementation SHOULD contain support for Operation   Privacy and Server Authentication as defined in the IPP/1.1 Encoding   and Transport document [RFC2910].  A Printer implementation MAY allow   an administrator to configure the degree of support for Operation   Privacy and Server Authentication.  See alsosection 8 of this   document.   Security MUST NOT be compromised when a client supplies a lower   "version-number" parameter in a request.  For example, if an IPP/1.1   conforming Printer object accepts version '1.0' requests and is   configured to enforce Digest Authentication, it MUST do the same for   a version '1.0' request.5.3 Charset and Natural Language Requirements   All clients and IPP objects MUST support the 'utf-8' charset as   defined insection 4.1.7.   IPP objects MUST be able to accept any client request which correctly   uses the "attributes-natural-language" operation attribute or the   Natural Language Override mechanism on any individual attribute   whether or not the natural language is supported by the IPP object.   If an IPP object supports a natural language, then it MUST be able to   translate (perhaps by table lookup) all generated 'text' or 'name'   attribute values into one of the supported languages (seesection3.1.4).  That is, the IPP object that supports a natural language   NEED NOT be a general purpose translator of any arbitrary 'text' or   'name' value supplied by the client into that natural language.   However, the object MUST be able to translate (automatically   generate) any of its own attribute values and messages into that   natural language.6. IANA Considerations   This section describes the procedures for defining semantics for the   following IETF standards track extensions and vendor extensions to   the IPP/1.1 Model and Semantics document:      1. keyword attribute values      2. enum attribute valuesHastings, et al.            Standards Track                   [Page 148]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      3. attributes      4. attribute syntaxes      5. operations      6. attribute groups      7. status codes      8. out-of-band attribute values   Extensions registered for use with IPP/1.1 are OPTIONAL for client   and IPP object conformance to the IPP/1.1 "Model and Semantics"   document (this document).   These extension procedures are aligned with the guidelines as set   forth by the IESG [IANA-CON].Section 11 describes how to propose   new registrations for consideration.  IANA will reject registration   proposals that leave out required information or do not follow the   appropriate format described inSection 11.  The IPP/1.1 Model and   Semantics document may also be extended by an appropriate RFC that   specifies any of the above extensions.6.1 Typed 'keyword' and 'enum' Extensions   IPP allows for 'keyword' and 'enum' extensions (see sections4.1.2.3   and 4.1.4).  This document uses prefixes to the 'keyword' and 'enum'   basic attribute syntax type in order to communicate extra information   to the reader through its name. This extra information is not   represented in the protocol because it is unimportant to a client or   Printer object.  The list below describes the prefixes and their   meaning.      "type1":  This IPP specification document must be revised (or         another IETF standards track document which augments this         document) to add a new keyword or a new enum.  No vendor         defined keywords or enums are allowed.      "type2":  Implementers can, at any time, add new keyword or enum         values by proposing the complete specification to IANA:         iana@iana.org         IANA will forward the registration proposal to the IPP         Designated Expert who will review the proposal with a mailing         list that the Designated Expert keeps for this purpose.         Initially, that list will be the mailing list used by the IPP         WG:            ipp@pwg.org         even after the IPP WG is disbanded as permitted by [IANA-CON].Hastings, et al.            Standards Track                   [Page 149]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         The IPP Designated Expert is appointed by the IESG Area         Director responsible for IPP, according to [IANA-CON].         When a type2 keyword or enum is approved, the IPP Designated         Expert becomes the point of contact for any future maintenance         that might be required for that registration.      "type3":  Implementers can, at any time, add new keyword and enum         values by submitting the complete specification to IANA as for         type2 who will forward the proposal to the IPP Designated         Expert.  While no additional technical review is required, the         IPP Designated Expert may, at his/her discretion, forward the         proposal to the same mailing list as for type2 registrations         for advice and comment.         When a type3 keyword or enum is approved by the IPP Designated         Expert, the original proposer becomes the point of contact for         any future maintenance that might be required for that         registration.   For type2 and type3 keywords, the proposer includes the name of the   keyword in the registration proposal and the name is part of the   technical review.   After type2 and type3 enums specifications are approved, the IPP   Designated Expert in consultation with IANA assigns the next   available enum number for each enum value.   IANA will publish approved type2 and type3 keyword and enum   attributes value registration specifications in:      ftp.isi.edu/iana/assignments/ipp/attribute-values/xxx/yyy.txt   where xxx is the attribute name that specifies the initial values and   yyy.txt is a descriptive file name that contains one or more enums or   keywords approved at the same time.  For example, if several   additional enums for stapling are approved for use with the   "finishings" attribute (and "finishings-default" and "finishings-   supported" attributes), IANA will publish the additional values in   the file:      ftp.isi.edu/iana/assignments/ipp/attribute-      values/finishings/stapling.txt   Note: Some attributes are defined to be: 'type3 keywords' | 'name'   which allows for attribute values to be extended by a site   administrator with administrator defined names.  Such names are not   registered with IANA.Hastings, et al.            Standards Track                   [Page 150]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   By definition, each of the three types above assert some sort of   registry or review process in order for extensions to be considered   valid.  Each higher numbered level (1, 2, 3) tends to be decreasingly   less stringent than the previous level.   Therefore, any typeN value   MAY be registered using a process for some typeM where M is less than   N, however such registration is NOT REQUIRED.  For example, a type3   value MAY be registered in a type 1 manner (by being included in a   future version of an IPP specification), however, it is NOT REQUIRED.   This document defines keyword and enum values for all of the above   types, including type3 keywords.   For vendor keyword extensions, implementers SHOULD use keywords with   a suitable distinguishing prefix, such as "xxx-" where xxx follows   the syntax rules for keywords (seesection 4.1.3) and is the   (lowercase) fully qualified company name registered with IANA for use   in domain names [RFC1035].  For example, if the company XYZ Corp. had   obtained the domain name "XYZ.com", then a vendor keyword 'abc' would   be: 'xyz.com-abc'.   Note:RFC 1035 [RFC1035] indicates that while upper and lower case   letters are allowed in domain names, no significance is attached to   the case.  That is, two names with the same spelling but different   case are to be treated as if identical.  Also, the labels in a domain   name must follow the rules for ARPANET host names:  They must start   with a letter, end with a letter or digit, and have as interior   characters only letters, digits, and hyphen.  Labels must be 63   characters or less.  Labels are separated by the "." character.   For vendor enum extensions, implementers MUST use values in the   reserved integer range which is 2**30 to 2**31-1.6.2 Attribute Extensibility   Attribute names (seesection 4.1.3) are type2 keywords.  Therefore,   new attributes may be registered and have the same status as   attributes in this document by following the type2 extension rules.   For vendor attribute extensions, implementers SHOULD use keywords   with a suitable distinguishing prefix as described inSection 6.1.   IANA will publish approved attribute registration specifications as   separate files:      ftp.isi.edu/iana/assignments/ipp/attributes/xxx-yyy.txt   where "xxx-yyy" is the new attribute name.Hastings, et al.            Standards Track                   [Page 151]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   If a new Printer object attribute is defined and its values can be   affected by a specific document format, its specification needs to   contain the following sentence:         "The value of this attribute returned in a Get-Printer-         Attributes response MAY depend on the "document-format"         attribute supplied (seeSection 3.2.5.1)."   If the specification does not, then its value in the Get-Printer-   Attributes response MUST NOT depend on the "document-format" supplied   in the request.  When a new Job Template attribute is registered, the   value of the Printer attributes MAY vary with "document-format"   supplied in the request without the specification having to indicate   so.6.3 Attribute Syntax Extensibility   Attribute syntaxes (seesection 4.1) are like type2 enums.   Therefore, new attribute syntaxes may be registered and have the same   status as attribute syntaxes in this document by following the type2   extension rules described inSection 6.1.  The initial set of value   codes that identify each of the attribute syntaxes have been assigned   in the "Encoding and Transport" document [RFC2910], including a   designated range for vendor extension.   For attribute syntaxes, the IPP Designated Expert in consultation   with IANA assigns the next attribute syntax code in the appropriate   range as specified in [RFC2910].  IANA will publish approved   attribute syntax registration specifications as separate files:      ftp.isi.edu/iana/assignments/ipp/attribute-syntaxes/xxx-yyy.txt   where 'xxx-yyy' is the new attribute syntax name.6.4 Operation Extensibility   Operations (seesection 3) may also be registered following the type2   procedures described inSection 6.1, though major new operations will   usually be done by a new standards track RFC that augments this   document.  For vendor operation extensions, implementers MUST use the   range for the "operation-id" in requests specified inSection 4.4.15   "operations-supported" Printer attribute.   For operations, the IPP Designated Expert in consultation with IANA   assigns the next operation-id code as specified inSection 4.4.15.   IANA will publish approved operation registration specifications as   separate files:Hastings, et al.            Standards Track                   [Page 152]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      ftp.isi.edu/iana/assignments/ipp/operations/Xxx-Yyy.txt   where "Xxx-Yyy" is the new operation name.6.5 Attribute Group Extensibility   Attribute groups (seesection 3.1.3) passed in requests and responses   may be registered following the type2 procedures described inSection6.1.  The initial set of attribute group tags have been assigned in   the "Encoding and Transport" document [RFC2910], including a   designated range for vendor extension.   For attribute groups, the IPP Designated Expert in consultation with   IANA assigns the next attribute group tag code in the appropriate   range as specified in [RFC2910].  IANA will publish approved   attribute group registration specifications as separate files:      ftp.isi.edu/iana/assignments/ipp/attribute-group-tags/xxx-yyy-      tag.txt   where 'xxx-yyy-tag' is the new attribute group tag name.6.6 Status Code Extensibility   Operation status codes (seesection 3.1.6.1) may also be registered   following the type2 procedures described inSection 6.1.  The values   for status codes are allocated in ranges as specified inSection 14   for each status code class:      "informational" - Request received, continuing process      "successful" - The action was successfully received, understood, and         accepted      "redirection" - Further action must be taken in order to complete the         request      "client-error" - The request contains bad syntax or cannot be         fulfilled      "server-error" - The IPP object  failed to fulfill an apparently         valid request   For vendor operation status code extensions, implementers MUST use   the top of each range as specified inSection 13.   For operation status codes, the IPP Designated Expert in consultation   with IANA assigns the next status code in the appropriate class range   as specified inSection 13.  IANA will publish approved status code   registration specifications as separate files:      ftp.isi.edu/iana/assignments/ipp/status-codes/xxx-yyy.txtHastings, et al.            Standards Track                   [Page 153]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   where "xxx-yyy" is the new operation status code keyword.6.7 Out-of-band Attribute Value Extensibility   Out-of-band attribute values (see the beginning ofsection 4.1)   passed in requests and responses may be registered following the   type2 procedures described inSection 6.1.  The initial set of out-   of-band attribute value tags have been assigned in the "Encoding and   Transport" document [RFC2910].   For out-of-band attribute value tags, the IPP Designated Expert in   consultation with IANA assigns the next out-of-band attribute value   tag code in the appropriate range as specified in [RFC2910].  IANA   will publish approved out-of-band attribute value tags registration   specifications as separate files:      ftp.isi.edu/iana/assignments/ipp/out-of-band-attribute-value-      tags/xxx-yyy-tag.txt   where 'xxx-yyy-tag' is the new out-of-band attribute value tag name.6.8 Registration of MIME types/sub-types for document-formats   The "document-format" attribute's syntax is 'mimeMediaType'.  This   means that valid values are Internet Media Types (seeSection 4.1.9).RFC 2045 [RFC2045] defines the syntax for valid Internet media types.   IANA is the registry for all Internet media types.6.9 Registration of charsets for use in 'charset' attribute values   The "attributes-charset" attribute's syntax is 'charset'.  This means   that valid values are charsets names.  When a charset in the IANA   registry has more than one name (alias), the name labeled as   "(preferred MIME name)", if present, MUST be used (seeSection4.1.7).  IANA is the registry for charsets following the procedures   of [RFC2278].7. Internationalization Considerations   Some of the attributes have values that are text strings and names   which are intended for human understanding rather than machine   understanding (see the 'text' and 'name' attribute syntaxes in   Sections4.1.1 and4.1.2).   In each operation request, the client      - identifies the charset and natural language of the request which        affects each supplied 'text' and 'name' attribute value, andHastings, et al.            Standards Track                   [Page 154]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      - requests the charset and natural language for attributes        returned by the IPP object in operation responses (as described        inSection 3.1.4.1).   In addition, the client MAY separately and individually identify the   Natural Language Override of a supplied 'text' or 'name' attribute   using the 'textWithLanguage' and 'nameWithLanguage' technique   describedsection 4.1.1.2 and 4.1.2.2 respectively.   All IPP objects MUST support the UTF-8 [RFC2279] charset in all   'text' and 'name' attributes supported.  If an IPP object supports   more than the UTF-8 charset, the object MUST convert between them in   order to return the requested charset to the client according toSection 3.1.4.2.  If an IPP object supports more than one natural   language, the object SHOULD return 'text' and 'name' values in the   natural language requested where those values are generated by the   Printer (seeSection 3.1.4.1).   For Printers that support multiple charsets and/or multiple natural   languages in 'text' and 'name' attributes, different jobs may have   been submitted in differing charsets and/or natural languages.  All   responses MUST be returned in the charset requested by the client.   However, the Get-Jobs operation uses the 'textWithLanguage' and   'nameWithLanguage' mechanism to identify the differing natural   languages with each job attribute returned.   The Printer object also has configured charset and natural language   attributes.   The client can query the Printer object to determine   the list of charsets and natural languages supported by the Printer   object and what the Printer object's configured values are.  See the   "charset-configured", "charset-supported", "natural-language-   configured", and "generated-natural-language-supported" Printer   description attributes for more details.   The "charset-supported" attributed identifies the supported charsets.   If a charset is supported, the IPP object MUST be capable of   converting to and from that charset into any other supported charset.   In many cases, an IPP object will support only one charset and it   MUST be the UTF-8 charset.   The "charset-configured" attribute identifies the one supported   charset which is the native charset given the current configuration   of the IPP object (administrator defined).   The "generated-natural-language-supported" attribute identifies the   set of supported natural languages for generated messages; it is not   related to the set of natural languages that must be accepted for   client supplied 'text' and 'name' attributes.  For client suppliedHastings, et al.            Standards Track                   [Page 155]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   'text' and 'name' attributes, an IPP object MUST accept ALL supplied   natural languages.  Just because a Printer object is currently   configured to support 'en-us' natural language does not mean that the   Printer object should reject a job if the client supplies a job name   that is in 'fr-ca'.   The "natural-language-configured" attribute identifies the one   supported natural language for generated messages which is the native   natural language given the current configuration of the IPP object   (administrator defined).   Attributes of type 'text' and 'name' are populated from different   sources.  These attributes can be categorized into following groups   (depending on the source of the attribute):      1. Some attributes are supplied by the client (e.g., the client         supplied "job-name", "document-name", and "requesting-user-         name" operation attributes along with the corresponding Job         object's "job-name" and "job-originating-user-name"         attributes).  The IPP object MUST accept these attributes in         any natural language no matter what the set of supported         languages for generated messages      2. Some attributes are supplied by the system administrator (e.g.,         the Printer object's "printer-name" and "printer-location"         attributes).  These too can be in any natural language.  If the         natural language for these attributes is different than what a         client requests, then they must be reported using the Natural         Language Override mechanism.      3. Some attributes are supplied by the device manufacturer (e.g.,         the Printer object's "printer-make-and-model" attribute).         These too can be in any natural language.  If the natural         language for these attributes is different than what a client         requests, then they must be reported using the Natural Language         Override mechanism.      4. Some attributes are supplied by the operator (e.g., the Job         object's "job-message-from-operator" attribute). These too can         be in any natural language.  If the natural language for these         attributes is different than what a client requests, then they         must be reported using the Natural Language Override mechanism.      5. Some attributes are generated by the IPP object (e.g., the Job         object's "job-state-message" attribute, the Printer object's         "printer-state-message" attribute, and the "status-message"         operation attribute).  These attributes can only be in one of         the "generated-natural-language-supported" natural languages.         If a client requests some natural language for these attributes         other than one of the supported values, the IPP object SHOULDHastings, et al.            Standards Track                   [Page 156]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         respond using the value of the "natural-language-configured"         attribute (using the Natural Language Override mechanism if         needed).   The 'text' and 'name' attributes specified in this version of this   document (additional ones will be registered according to the   procedures inSection 6) are:                    Attributes                            Source   Operation Attributes:        job-name (name)                         client        document-name (name)                    client        requesting-user-name (name)             client        status-message (text)                   Job or Printer object        detailed-status-message (text)          Job or Printer object -                                                see rule 1        document-access-error (text)            Job or Printer object -                                                see rule 1   Job Template Attributes:        job-hold-until (keyword | name)         client matches                                                administrator-configured        job-hold-until-default (keyword | name) client matches                                                administrator-configured        job-hold-until-supported (keyword |     client matches        name)                                   administrator-configured        job-sheets (keyword | name)             client matches                                                administrator-configured        job-sheets-default (keyword | name)     client matches                                                administrator-configured        job-sheets-supported (keyword | name)   client matches                                                administrator-configured        media (keyword | name)                  client matches                                                administrator-configured        media-default (keyword | name)          client matches                                                administrator-configured        media-supported (keyword | name)        client matches                                                administrator-configured        media-ready (keyword | name)            client matches                                                administrator-configured   Job Description Attributes:        job-name (name)                         client or Printer object        job-originating-user-name (name)        Printer object        job-state-message (text)                Job or Printer object        output-device-assigned (name(127))      administrator        job-message-from-operator (text(127))   operatorHastings, et al.            Standards Track                   [Page 157]

RFC 2911              IPP/1.1: Model and Semantics        September 2000        job-detailed-status-messages (1setOf    Job or Printer object -        text)                                   see rule 1        job-document-access-errors (1setOf      Job or Printer object -        text)                                   see rule 1   Printer Description Attributes:        printer-name (name(127))                administrator        printer-location (text(127))            administrator        printer-info (text(127))                administrator        printer-make-and-model (text(127))      administrator or                                                manufacturer        printer-state-message (text)            Printer object        printer-message-from-operator           operator        (text(127))   Rule 1 - Neither the Printer nor the client localizes these message   attributes, since they are intended for use by the system   administrator or other experienced technical persons.8. Security Considerations   It is difficult to anticipate the security risks that might exist in   any given IPP environment. For example, if IPP is used within a given   corporation over a private network, the risks of exposing document   data may be low enough that the corporation will choose not to use   encryption on that data.  However, if the connection between the   client and the IPP object is over a public network, the client may   wish to protect the content of the information during transmission   through the network with encryption.   Furthermore, the value of the information being printed may vary from   one IPP environment to the next. Printing payroll checks, for   example, would have a different value than printing public   information from a file.  There is also the possibly of denial-of-   service attacks, but denial-of-service attacks against printing   resources are not well understood and there is no published   precedents regarding this scenario.   Once the authenticated identity of the requester has been supplied to   the IPP object, the object uses that identity to enforce any   authorization policy that might be in place.  For example, one site's   policy might be that only the job owner is allowed to cancel a job.   The details and mechanisms to set up a particular access control   policy are not part of IPP/1.1, and must be established via some   other type of administrative or access control framework.  However,   there are operation status codes that allow an IPP server to return   information back to a client about any potential access control   violations for an IPP object.Hastings, et al.            Standards Track                   [Page 158]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   During a create operation, the client's identity is recorded in the   Job object in an implementation-defined attribute.  This information   can be used to verify a client's identity for subsequent operations   on that Job object in order to enforce any access control policy that   might be in effect.  Seesection 8.3 below for more details.   Since the security levels or the specific threats that an IPP system   administrator may be concerned with cannot be anticipated, IPP MUST   be capable of operating with different security mechanisms and   security policies as required by the individual installation.   Security policies might vary from very strong, to very weak, to none   at all, and corresponding security mechanisms will be required.8.1 Security Scenarios   The following sections describe specific security attacks for IPP   environments.  Where examples are provided they should be considered   illustrative of the environment and not an exhaustive set. Not all of   these environments will necessarily be addressed in initial   implementations of IPP.8.1.1 Client and Server in the Same Security Domain   This environment is typical of internal networks where traditional   office workers print the output of personal productivity applications   on shared work-group printers, or where batch applications print   their output on large production printers. Although the identity of   the user may be trusted in this environment, a user might want to   protect the content of a document against such attacks as   eavesdropping, replaying or tampering.8.1.2 Client and Server in Different Security Domains   Examples of this environment include printing a document created by   the client on a publicly available printer, such as at a commercial   print shop; or printing a document remotely on a business associate's   printer.  This latter operation is functionally equivalent to sending   the document to the business associate as a facsimile. Printing   sensitive information on a Printer in a different security domain   requires strong security measures. In this environment authentication   of the printer is required as well as protection against unauthorized   use of print resources. Since the document crosses security domains,   protection against eavesdropping and document tampering are also   required. It will also be important in this environment to protect   Printers against "spamming" and malicious document content.Hastings, et al.            Standards Track                   [Page 159]

RFC 2911              IPP/1.1: Model and Semantics        September 20008.1.3 Print by Reference   When the document is not stored on the client, printing can be done   by reference. That is, the print request can contain a reference, or   pointer, to the document instead of the actual document itself (see   sections3.2.2 and3.3.2). Standard methods currently do not exist   for remote entities to "assume" the credentials of a client for   forwarding requests to a 3rd party. It is anticipated that Print-By-   Reference will be used to access "public" documents and that   sophisticated methods for authenticating "proxies" is not specified   in this document.8.2 URIs in Operation, Job, and Printer attributes   The "printer-uri-supported" attribute contains the Printer object's   URI(s).  Its companion attribute, "uri-security-supported",   identifies the security mechanism used for each URI listed in the   "printer-uri-supported" attribute.  For each Printer operation   request, a client MUST supply only one URI in the "printer-uri"   operation attribute.  In other words, even though the Printer   supports more than one URI, the client only interacts with the   Printer object using one if its URIs.  This duality is not needed for   Job objects, since the Printer objects is the factory for Job   objects, and the Printer object will generate the correct URI for new   Job objects depending on the Printer object's security configuration.8.3 URIs for each authentication mechanisms   Each URI has an authentication mechanism associated with it. If the   URI is the i'th element of "printer-uri-supported", then   authentication mechanism is the "i th" element of "uri-   authentication-supported". For a list of possible authentication   mechanisms, seesection 4.4.2.   The Printer object uses an authentication mechanism to determine the   name of the user performing an operation. This user is called the   "authenticated user". The credibility of authentication depends on   the mechanism that the Printer uses to obtain the user's name. When   the authentication mechanism is 'none', all authenticated users are   "anonymous".   During job creation operations, the Printer initializes the value of   the "job-originating-user-name" attribute (seesection 4.3.6) to be   the authenticated user. The authenticated user is this case is called   the "job owner".Hastings, et al.            Standards Track                   [Page 160]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   If an implementation can be configured to support more than one   authentication mechanism (seesection 4.4.2), then it MUST implement   rules for determining equality of authenticated user names which have   been authenticated via different authentication mechanisms.  One   possible policy is that identical names that are authenticated via   different mechanisms are different.  For example, a user can cancel   his job only if he uses the same authentication mechanism for both   Cancel-Job and Print-Job.  Another policy is that identical names   that are authenticated via different mechanism are the same if the   authentication mechanism for the later operation is not less strong   than the authentication mechanism for the earlier job creation   operation.  For example, a user can cancel his job only if he uses   the same or stronger authentication mechanism for Cancel-Job and   Print-Job. With this second policy a job submitted via 'requesting-   user-name' authentication could be canceled via 'digest'   authentication. With the first policy, the job could not be canceled   in this way.   A client is able to determine the authentication mechanism used to   create a job. It is the i'th value of the Printer's "uri-   authentication-supported" attribute (seesection 4.4.2), where i is   the index of the element of the Printer's "printer-uri-supported"   attribute (seesection 4.4.1) equal to the job's "job-printer-uri"   attribute (seesection 4.3.3).8.4 Restricted Queries   In many IPP operations, a client supplies a list of attributes to be   returned in the response.  For security reasons, an IPP object may be   configured not to return all attributes (or all values) that a client   requests.  The job attributes returned MAY depend on whether the   requesting user is the same as the user that submitted the job. The   IPP object MAY even return none of the requested attributes. In such   cases, the status returned is the same as if the object had returned   all requested attributes.  The client cannot tell by such a response   whether the requested attribute was present or absent on the object.8.5 Operations performed by operators and system administrators   For the three printer operations Pause-Printer, Resume-Printer, and   Purge-Jobs (see sections3.2.7,3.2.8 and3.2.9), the requesting user   is intended to be an operator or administrator of the Printer object   (seesection 1).  Otherwise, the IPP Printer MUST reject the   operation and return:  'client-error-forbidden', 'client-error-not-   authenticated', or 'client-error-not-authorized' as appropriate.  For   operations on jobs, the requesting user is intended to be the jobHastings, et al.            Standards Track                   [Page 161]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   owner or may be an operator or administrator of the Printer object.   The means for authorizing an operator or administrator of the Printer   object are not specified in this document.8.6 Queries on jobs submitted using non-IPP protocols   If the device that an IPP Printer is representing is able to accept   jobs using other job submission protocols in addition to IPP, it is   RECOMMENDED that such an implementation at least allow such "foreign"   jobs to be queried using Get-Jobs returning "job-id" and "job-uri" as   'unknown'.  Such an implementation NEED NOT support all of the same   IPP job attributes as for IPP jobs.  The IPP object returns the   'unknown' out-of-band value for any requested attribute of a foreign   job that is supported for IPP jobs, but not for foreign jobs.   It is further RECOMMENDED, that the IPP Printer generate "job-id" and   "job-uri" values for such "foreign jobs", if possible, so that they   may be targets of other IPP operations, such as Get-Job-Attributes   and Cancel-Job.  Such an implementation also needs to deal with the   problem of authentication of such foreign jobs.  One approach would   be to treat all such foreign jobs as belonging to users other than   the user of the IPP client.  Another approach would be for the   foreign job to belong to 'anonymous'.  Only if the IPP client has   been authenticated as an operator or administrator of the IPP Printer   object, could the foreign jobs be queried by an IPP request.   Alternatively, if the security policy is to allow users to query   other users' jobs, then the foreign jobs would also be visible to an   end-user IPP client using Get-Jobs and Get-Job-Attributes.9. References   [ASME-Y14.1M] Metric Drawing Sheet Size and Format, ASME Y14.1M-1995.                 This standard defines metric sheet sizes and formats                 for engineering drawings.   [ASCII]       Coded Character Set - 7-bit American Standard Code for                 Information Interchange (ASCII), ANSI X3.4-1986. This                 standard is the specification of the US-ASCII charset.   [BCP-11]      Bradner S. and R. Hovey, "The Organizations Involved in                 the IETF Standards Process",BCP 11,RFC 2028, October                 1996.   [HTPP]        J. Barnett, K. Carter, R. DeBry,  "Initial Draft -                 Hypertext Printing Protocol - HTPP/1.0", October 1996,ftp://ftp.pwg.org/pub/pwg/ipp/historic/htpp/overview.ps.gzHastings, et al.            Standards Track                   [Page 162]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   [IANA-CON]    Narten, T. and H. Alvestrand, "Guidelines for Writing                 an IANA Considerations Section in RFCs",BCP 26,RFC2434, October 1998.   [IANA-CS]     IANA Registry of Coded Character Sets:ftp://ftp.isi.edu/in-notes/iana/assignments/character-sets   [IANA-MT]     IANA Registry of Media Types:ftp://ftp.isi.edu/in-notes/iana/assignments/media-types/   [IPP-IIG]     Hastings, T., Manros, C., Kugler, C., Holst, H., and P.                 Zehler, "Internet Printing Protocol/1.1:draft-ietf-ipp-implementers-guide-v11-01.txt, work in progress,                 May 30, 2000.   [ISO10646-1]  ISO/IEC 10646-1:1993, "Information technology --                 Universal Multiple-Octet Coded Character Set (UCS) -                 Part 1: Architecture and Basic Multilingual Plane,                 JTC1/SC2."   [ISO8859-1]   ISO/IEC 8859-1:1987, "Information technology -- 8-bit                 One-Byte Coded Character Set - Part 1: Latin Alphabet                 Nr 1", 1987, JTC1/SC2.   [ISO10175]    ISO/IEC 10175 Document Printing Application (DPA), June                 1996.   [LDPA]        T. Hastings,  S. Isaacson,  M. MacKay, C. Manros, D.                 Taylor, P. Zehler,  "LDPA - Lightweight Document                 Printing Application", October 1996,ftp://ftp.pwg.org/pub/pwg/ipp/historic/ldpa/ldpa8.pdf.gz   [P1387.4]     Kirk, M. (editor), POSIX System Administration - Part                 4:  Printing Interfaces, POSIX 1387.4 D8, 1994.   [PSIS]        Herriot, R. (editor), X/Open A Printing System                 Interoperability Specification (PSIS), August 1995.   [PWG]         Printer Working Group,http://www.pwg.org.   [RFC1035]     Mockapetris, P., "Domain Names - Implementation and                 Specification", STD 13,RFC 1035, November 1987.   [RFC1179]     McLaughlin, L., "Line Printer Daemon Protocol",RFC1179, August 1990.Hastings, et al.            Standards Track                   [Page 163]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   [RFC1759]     Smith, R., Wright, F., Hastings, T., Zilles, S. and J.                 Gyllenskog, "Printer MIB",RFC 1759, March 1995.   [RFC1766]     Alvestrand, H., "Tags for the Identification of                 Languages",RFC 1766, March 1995.   [RFC1951]     Deutsch, P., "DEFLATE Compressed Data Format                 Specification version 1.3 ",RFC 1951, May 1996.   [RFC1952]     Deutsch, P., "GZIP file format specification version                 4.3",RFC 1952, May 1996.   [RFC1977]     Schryver, V., "PPP BSD Compression Protocol",RFC 1977,                 August 1996.   [RFC2026]     Bradner, S., "The Internet Standards Process --                 Revision 3",BCP 9,RFC 2026, October 1996.   [RFC2045]     Freed, N. and  N. Borenstein, ", Multipurpose Internet                 Mail Extensions (MIME) Part One: Format of Internet                 Message Bodies",RFC 2045, November 1996.   [RFC2046]     Freed, N. and N. Borenstein, "Multipurpose Internet                 Mail Extensions (MIME) Part Two: Media Types",RFC2046, November 1996.   [RFC2048]     Freed, N., Klensin, J. and J. Postel, "Multipurpose                 Internet Mail Extension (MIME) Part Four: Registration                 Procedures",RFC 2048, November 1996.   [RFC2119]     Bradner, S., "Key words for use in RFCs to Indicate                 Requirement Levels",BCP 14,RFC 2119, March 1997.   [RFC2228]     Horowitz, M. and S. Lunt, "FTP Security Extensions",RFC 2228, October 1997.   [RFC2246]     Dierks, T. and C. Allen, "The TLS Protocol Version                 1.0",RFC 2246, January 1999.   [RFC2277]     Alvestrand, H., "IETF Policy on Character Sets and                 Languages"BCP 18,RFC 2277, January 1998.   [RFC2278]     Freed, N. and J. Postel: "IANA CharSet Registration                 Procedures",BCP 19,RFC 2278, January 1998.   [RFC2279]     Yergeau, F., "UTF-8, a transformation format of ISO                 10646",RFC 2279, January 1998.Hastings, et al.            Standards Track                   [Page 164]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   [RFC2316]     Bellovin, S., "Report of the IAB Security Architecture                 Workshop",RFC 2316, April 1998.   [RFC2396]     Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform                 Resource Identifiers (URI): Generic Syntax",RFC 2396,                 August 1998.   [RFC2565]     Herriot, R., Butler, S., Moore, P. and R. Turner,                 "Internet Printing Protocol/1.0: Encoding and                 Transport",RFC 2565, April 1999.   [RFC2566]     deBry, R., Hastings, T., Herriot, R., Isaacson, S. and                 P. Powell, "Internet Printing Protocol/1.0: Model and                 Semantics",RFC 2566, April 1999.   [RFC2567]     Wright, D., "Design Goals for an Internet Printing                 Protocol",RFC 2567, April 1999.   [RFC2568]     Zilles, S., "Rationale for the Structure and Model and                 Protocol for the Internet Printing Protocol",RFC 2568,                 April 1999.   [RFC2569]     Herriot, R., Hastings, T., Jacobs, N. and J. Martin,                 "Mapping between LPD and IPP Protocols",RFC 2569,                 April 1999.   [RFC2579]     McCloghrie, K., Perkins, D. and J. Schoenwaelder,                 "Textual Conventions for SMIv2", STD 58,RFC 2579,                 April 1999.   [RFC2616]     Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,                 Masinter, L., Leach, P. and T. Berners-Lee, "Hypertext                 Transfer Protocol - HTTP/1.1",RFC 2616, June 1999.   [RFC2617]     Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence,                 S., Leach, P., Luotonen, A. and L. Stewart, "HTTP                 Authentication:  Basic and Digest Access                 Authentication",RFC 2617, June 1999.   [RFC2639]     Hastings, T. and C. Manros, "Internet Printing                 Protocol/1.0: Encoding and Transport",RFC 2639, July                 1999.   [RFC2910]     Herriot, R., Butler, S., Moore, P., Turner, R. and J.                 Wenn, "Internet Printing Protocol/1.1: Encoding and                 Transport",RFC 2910, September 2000.Hastings, et al.            Standards Track                   [Page 165]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   [SSL]         Netscape, The SSL Protocol, Version 3, (Text version                 3.02), November 1996.   [SWP]         P. Moore, B. Jahromi, S. Butler, "Simple Web Printing                 SWP/1.0", May 7, 1997,ftp://ftp.pwg.org/pub/pwg/ipp/new_PRO/swp9705.pdf10. Authors' Addresses   Scott A. Isaacson, Editor   Novell, Inc.   122 E 1700 S   Provo, UT   84606   Phone: 801-861-7366   Fax:   801-861-2517   EMail: sisaacson@novell.com   Tom Hastings   Xerox Corporation   737 Hawaii St.  ESAE 231   El Segundo, CA   90245   Phone: 310-333-6413   Fax:   310-333-5514   EMail: hastings@cp10.es.xerox.com   Robert Herriot   Xerox Corp.   3400 Hill View Ave, Building 1   Palo Alto, CA 94304   Phone: 650-813-7696   Fax:  650-813-6860   EMail: robert.herriot@pahv.xerox.com   Roger deBry   Utah Valley State College   Orem, UT 84058   Phone: (801) 222-8000   EMail: debryro@uvsc.eduHastings, et al.            Standards Track                   [Page 166]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Patrick Powell   Astart Technologies   9475 Chesapeake Dr., Suite D   San Diego, CA  95123   Phone: (619) 874-6543   Fax:   (619) 279-8424   EMail: papowell@astart.com   IPP Web Page:http://www.pwg.org/ipp/IPP Mailing List:  ipp@pwg.org   To subscribe to the ipp mailing list, send the following email:      1) send it to majordomo@pwg.org      2) leave the subject line blank      3) put the following two lines in the message body:            subscribe ipp            end   Implementers of this specification document are encouraged to join   IPP Mailing List in order to participate in any discussions of   clarification issues and review of registration proposals for   additional attributes and values.   Other Participants:   Chuck Adams - Tektronix             Shivaun Albright - HP   Stefan Andersson - Axis             Jeff Barnett - IBM   Ron Bergman - Hitachi Koki Imaging  Dennis Carney - IBM   Systems   Keith Carter - IBM                  Angelo Caruso - Xerox   Rajesh Chawla - TR Computing        Nancy Chen - Okidata   Solutions   Josh Cohen - Microsoft              Jeff Copeland - QMS   Andy Davidson - Tektronix           Roger deBry - IBM   Maulik Desai - Auco                 Mabry Dozier - QMS   Lee Farrell - Canon Information     Satoshi Fujitami - Ricoh   Systems   Steve Gebert - IBM                  Sue Gleeson - Digital   Charles Gordon - Osicom             Brian Grimshaw - Apple   Jerry Hadsell - IBM                 Richard Hart - Digital   Tom Hastings - Xerox                Henrik Holst - I-data   Stephen Holmstead                   Zhi-Hong Huang - Zenographics   Scott Isaacson - Novell             Babek Jahromi - Microsoft   Swen Johnson - Xerox                David Kellerman - Northlake                                       Software   Robert Kline - TrueSpectra          Charles Kong - Panasonic   Carl Kugler - IBM                   Dave Kuntz - Hewlett-PackardHastings, et al.            Standards Track                   [Page 167]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Takami Kurono - Brother             Rick Landau - Digital   Scott Lawrence - Agranot Systems    Greg LeClair - Epson   Dwight Lewis - Lexmark              Harry Lewis - IBM   Tony Liao - Vivid Image             Roy Lomicka - Digital   Pete Loya - HP                      Ray Lutz - Cognisys   Mike MacKay - Novell, Inc.          David Manchala - Xerox   Carl-Uno Manros - Xerox             Jay Martin - Underscore   Stan McConnell - Xerox              Larry Masinter - Xerox   Sandra Matts - Hewlett Packard      Peter Michalek - Shinesoft   Ira McDonald - High North Inc.      Mike Moldovan - G3 Nova   Tetsuya Morita - Ricoh              Yuichi Niwa - Ricoh   Pat Nogay - IBM                     Ron Norton - Printronics   Hugo Parra, Novell                  Bob Pentecost - Hewlett-Packard   Patrick Powell - Astart             Jeff Rackowitz - Intermec   Technologies   Eric Random - Peerless              Rob Rhoads - Intel   Xavier Riley - Xerox                Gary Roberts - Ricoh   David Roach - Unisys                Stuart Rowley - Kyocera   Yuji Sasaki - Japan Computer        Richard Schneider - Epson   Industry   Kris Schoff - HP                    Katsuaki Sekiguchi - Canon   Bob Setterbo - Adobe                Gail Songer - Peerless   Hideki Tanaka - Cannon              Devon Taylor - Novell   Mike Timperman - Lexmark            Atsushi Uchino - Epson   Shigeru Ueda - Canon                Bob Von Andel - Allegro Software   William Wagner - NetSilicon/DPI     Jim Walker - DAZEL   Chris Wellens - Interworking Labs   Trevor Wells - Hewlett Packard   Craig Whittle - Sharp Labs          Rob Whittle - Novell, Inc.   Jasper Wong - Xionics               Don Wright - Lexmark   Michael Wu - Heidelberg Digital     Rick Yardumian - Xerox   Michael Yeung - Toshiba             Lloyd Young - Lexmark   Atsushi Yuki - Kyocera              Peter Zehler - Xerox   William Zhang- Canon Information    Frank Zhao - Panasonic   Systems   Steve Zilles - Adobe                Rob Zirnstein - Canon Information                                       Systems11. Formats for IPP Registration Proposals   In order to propose an IPP extension for registration, the proposer   must submit an application to IANA by email to "iana@iana.org" or by   filling out the appropriate form on the IANA web pages   (http://www.iana.org).  This section specifies the required   information and the formats for proposing registrations of extensions   to IPP as provided inSection 6 for:Hastings, et al.            Standards Track                   [Page 168]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      1. type2 'keyword' attribute values      2. type3 'keyword' attribute values      3. type2 'enum' attribute values      4. type3 'enum' attribute values      5. attributes      6. attribute syntaxes      7. operations      8. status codes      9. out-of-band attribute values11.1 Type2 keyword attribute values registration,   Type of registration:  type2 keyword attribute value   Name of attribute to which this keyword specification is to be added:   Proposed keyword name of this keyword value:   Specification of this keyword value (follow the style of IPP ModelSection 4.1.2.3):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For type2 keywords, the Designated Expert will be the point of   contact for the approved registration specification, if any   maintenance of the registration specification is needed.11.2 Type3 keyword attribute values registration   Type of registration:  type3 keyword attribute value   Name of attribute to which this keyword specification is to be added:   Proposed keyword name of this keyword value:   Specification of this keyword value (follow the style of IPP ModelSection 4.1.2.3):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For type3 keywords, the proposer will be the point of contact   for the approved registration specification, if any maintenance of   the registration specification is needed.11.3 Type2 enum attribute values registration   Type of registration:  type2 enum attribute value   Name of attribute to which this enum specification is to be added:   Keyword symbolic name of this enum value:   Numeric value (to be assigned by the IPP Designated Expert in   consultation with IANA):Hastings, et al.            Standards Track                   [Page 169]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Specification of this enum value (follow the style of IPP ModelSection 4.1.4):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For type2 enums, the Designated Expert will be the point of   contact for the approved registration specification, if any   maintenance of the registration specification is needed.11.4 Type3 enum attribute values registration   Type of registration:  type3 enum attribute value   Name of attribute to which this enum specification is to be added:   Keyword symbolic name of this enum value:   Numeric value (to be assigned by the IPP Designated Expert in   consultation with IANA):   Specification of this enum value (follow the style of IPP ModelSection 4.1.4):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For type3 enums, the proposer will be the point of contact for   the approved registration specification, if any maintenance of the   registration specification is needed.11.5 Attribute registration   Type of registration:  attribute   Proposed keyword name of this attribute:   Types of attribute (Operation, Job Template, Job Description, Printer   Description):   Operations to be used with if the attribute is an operation attribute:   Object (Job, Printer, etc. if bound to an object):   Attribute syntax(es) (include 1setOf and range as inSection 4.2):   If attribute syntax is 'keyword' or 'enum', is it type2 or type3:   If this is a Printer attribute, MAY the value returned depend on   "document-format" (SeeSection 6.2):   If this is a Job Template attribute, how does its specification depend   on the value of the "multiple-document-handling" attribute:   Specification of this attribute (follow the style of IPP ModelSection4.2):   Name of proposer:   Address of proposer:   Email address of proposer:Hastings, et al.            Standards Track                   [Page 170]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Note:  For attributes, the IPP Designated Expert will be the point of   contact for the approved registration specification, if any   maintenance of the registration specification is needed.11.6 Attribute Syntax registration   Type of registration:  attribute syntax   Proposed name of this attribute syntax:   Type of attribute syntax (integer, octetString, character-string,  see   [RFC2910]):   Numeric tag according to [RFC2910] (to be assigned by the IPP   Designated Expert in consultation with IANA):   Specification of this attribute (follow the style of IPP ModelSection4.1):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For attribute syntaxes, the IPP Designated Expert will be the   point of contact for the approved registration specification, if any   maintenance of the registration specification is needed.11.7 Operation registration   Type of registration:  operation   Proposed name of this operation:   Numeric operation-id value according tosection 4.4.15 (to be assigned   by the IPP Designated Expert in consultation with IANA):   Object Target (Job, Printer, etc. that operation is upon):   Specification of this operation (follow the style of IPP ModelSection3):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For operations, the IPP Designated Expert will be the point of   contact for the approved registration specification, if any   maintenance of the registration specification is needed.11.8 Attribute Group registration   Type of registration:  attribute group   Proposed name of this attribute group:   Numeric tag according to [RFC2910] (to be assigned by the IPP   Designated Expert in consultation with IANA):   Operation requests and group number for each operation in which the   attribute group occurs:Hastings, et al.            Standards Track                   [Page 171]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Operation responses and group number for each operation in which the   attribute group occurs:   Specification of this attribute group (follow the style of IPP ModelSection 3):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For attribute groups, the IPP Designated Expert will be the   point of contact for the approved registration specification, if any   maintenance of the registration specification is needed.11.9 Status code registration   Type of registration:  status code   Keyword symbolic name of this status code value:   Numeric value (to be assigned by the IPP Designated Expert in   consultation with IANA):   Operations that this status code may be used with:   Specification of this status code (follow the style of IPP ModelSection 13 APPENDIX B:  Status Codes and Suggested Status Code   Messages):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For status codes, the Designated Expert will be the point of   contact for the approved registration specification, if any   maintenance of the registration specification is needed.11.10 Out-of-band Attribute Value registration   Type of registration:  out-of-band attribute value   Proposed name of this out-of-band attribute value:   Numeric tag according to [RFC2910] (to be assigned by the IPP Designated   Expert in consultation with IANA):   Operations that this out-of-band attribute value may be used with:   Attributes that this out-of-band attribute value may be used with:   Specification of this out-of-band attribute value (follow the style of   the beginning of IPP ModelSection 4.1):   Name of proposer:   Address of proposer:   Email address of proposer:   Note:  For out-of-band attribute values, the IPP Designated Expert   will be the point of contact for the approved registration   specification, if any maintenance of the registration specification   is needed.Hastings, et al.            Standards Track                   [Page 172]

RFC 2911              IPP/1.1: Model and Semantics        September 200012. APPENDIX A: Terminology   This specification document uses the terminology defined in this   section.12.1 Conformance Terminology   The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",   "RECOMMENDED", "MAY", and  "OPTIONAL" in this document are to be   interpreted as described inRFC 2119 [RFC2119].12.1.1 NEED NOT   This term is not included inRFC 2119.  The verb "NEED NOT" indicates   an action that the subject of the sentence does not have to implement   in order to claim conformance to the standard.  The verb "NEED NOT"   is used instead of "MAY NOT" since "MAY NOT" sounds like a   prohibition.12.2 Model Terminology12.2.1 Keyword   Keywords are used within this document as identifiers of semantic   entities within the abstract model (seesection 4.1.2.3).  Attribute   names, some attribute values, attribute syntaxes, and attribute group   names are represented as keywords.12.2.2 Attributes   An attribute is an item of information that is associated with an   instance of an IPP object.  An attribute consists of an attribute   name and one or more attribute values.  Each attribute has a specific   attribute syntax.  All object attributes are defined insection 4 and   all operation attributes are defined insection 3.   Job Template Attributes are described insection 4.2. The client   optionally supplies Job Template attributes in a create request   (operation requests that create Job objects).  The Printer object has   associated attributes which define supported and default values for   the Printer.12.2.2.1 Attribute Name   Each attribute is uniquely identified in this document by its   attribute name.  An attribute name is a keyword.  The keyword   attribute name is given in the section header describing thatHastings, et al.            Standards Track                   [Page 173]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   attribute.  In running text in this document, attribute names are   indicated inside double quotation marks (") where the quotation marks   are not part of the keyword itself.12.2.2.2 Attribute Group Name   Related attributes are grouped into named groups.  The name of the   group is a keyword.  The group name may be used in place of naming   all the attributes in the group explicitly.  Attribute groups are   defined insection 3.12.2.2.3 Attribute Value   Each attribute has one or more values.  Attribute values are   represented in the syntax type specified for that attribute. In   running text in this document, attribute values are indicated inside   single quotation marks ('), whether their attribute syntax is   keyword, integer, text, etc.  where the quotation marks are not part   of the value itself.12.2.2.4 Attribute Syntax   Each attribute is defined using an explicit syntax type.  In this   document, each syntax type is defined as a keyword with specific   meaning.  The "Encoding and Transport" document [RFC2910] indicates   the actual "on-the-wire" encoding rules for each syntax type.   Attribute syntax types are defined insection 4.1.12.2.3 Supports   By definition, a Printer object supports an attribute only if that   Printer object responds with the corresponding attribute populated   with some value(s) in a response to a query for that attribute.  A   Printer object supports an attribute value if the value is one of the   Printer object's "supported values" attributes.  The device behind a   Printer object may exhibit a behavior that corresponds to some IPP   attribute, but if the Printer object, when queried for that   attribute, doesn't respond with the attribute, then as far as IPP is   concerned, that implementation does not support that feature. If the   Printer object's "xxx-supported" attribute is not populated with a   particular value (even if that value is a legal value for that   attribute), then that Printer object does not support that particular   value.Hastings, et al.            Standards Track                   [Page 174]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   A conforming implementation MUST support all REQUIRED attributes.   However, even for REQUIRED attributes, conformance to IPP does not   mandate that all implementations support all possible values   representing all possible job processing behaviors and features.  For   example, if a given instance of a Printer supports only certain   document formats, then that Printer responds with the "document-   format-supported" attribute populated with a set of values, possibly   only one, taken from the entire set of possible values defined for   that attribute. This limited set of values represents the Printer's   set of supported document formats.  Supporting an attribute and some   set of values for that attribute enables IPP end users to be aware of   and make use of those features associated with that attribute and   those values.  If an implementation chooses to not support an   attribute or some specific value, then IPP end users would have no   ability to make use of that feature within the context of IPP itself.   However, due to existing practice and legacy systems which are not   IPP aware, there might be some other mechanism outside the scope of   IPP to control or request the "unsupported" feature (such as embedded   instructions within the document data itself).   For example, consider the "finishings-supported" attribute.      1) If a Printer object is not physically capable of stapling, the         "finishings-supported" attribute MUST NOT be populated with the         value of 'staple'.      2) A Printer object is physically capable of stapling, however an         implementation chooses not to support stapling in the IPP         "finishings" attribute.  In this case, 'staple' MUST NOT be a         value in the "finishings-supported" Printer object attribute.         Without support for the value 'staple', an IPP end user would         have no means within the protocol itself to request that a Job         be stapled.  However, an existing document data formatter might         be able to request that the document be stapled directly with         an embedded instruction within the document data.  In this         case, the IPP implementation does not "support" stapling,         however the end user is still able to have some control over         the stapling of the completed job.      3) A Printer object is physically capable of stapling, and an         implementation chooses to support stapling in the IPP         "finishings" attribute. In this case, 'staple' MUST be a value         in the "finishings-supported" Printer object attribute. Doing         so, would enable end users to be aware of and make use of the         stapling feature using IPP attributes.Hastings, et al.            Standards Track                   [Page 175]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Even though support for Job Template attributes by a Printer object   is OPTIONAL, it is RECOMMENDED that if the device behind a Printer   object is capable of realizing any feature or function that   corresponds to an IPP attribute and some associated value, then that   implementation SHOULD support that IPP attribute and value.   The set of values in any of the supported value attributes is set   (populated) by some administrative process or automatic sensing   mechanism that is outside the scope of this IPP/1.1 document.  For   administrative policy and control reasons, an administrator may   choose to make only a subset of possible values visible to the end   user.  In this case, the real output device behind the IPP Printer   abstraction may be capable of a certain feature, however an   administrator is specifying that access to that feature not be   exposed to the end user through the IPP protocol.  Also, since a   Printer object may represent a logical print device (not just a   physical device) the actual process for supporting a value is   undefined and left up to the implementation.  However, if a Printer   object supports a value, some manual human action may be needed to   realize the semantic action associated with the value, but no end   user action is required.   For example, if one of the values in the "finishings-supported"   attribute is 'staple', the actual process might be an automatic   staple action by a physical device controlled by some command sent to   the device.  Or, the actual process of stapling might be a manual   action by an operator at an operator attended Printer object.   For another example of how supported attributes function, consider a   system administrator who desires to control all print jobs so that no   job sheets are printed in order to conserve paper.  To force no job   sheets, the system administrator sets the only supported value for   the "job-sheets-supported" attribute to 'none'.  In this case, if a   client requests anything except 'none', the create request is   rejected or the "job-sheets" value is ignored (depending on the value   of "ipp-attribute-fidelity").  To force the use of job start/end   sheets on all jobs, the administrator does not include the value   'none' in the "job-sheets- supported" attribute.  In this case, if a   client requests 'none', the create request is rejected or the "job-   sheets" value is ignored (again depending on the value of "ipp-   attribute-fidelity").12.2.4 print-stream page   A "print-stream page" is a page according to the definition of pages   in the language used to express the document data.Hastings, et al.            Standards Track                   [Page 176]

RFC 2911              IPP/1.1: Model and Semantics        September 200012.2.5 impression   An "impression" is the image (possibly many print-stream pages in   different configurations) imposed onto a single media page.13. APPENDIX B:Status Codes and Suggested Status Code Messages   This section defines status code enum keywords and values that are   used to provide semantic information on the results of an operation   request.  Each operation response MUST include a status code.  The   response MAY also contain a status message that provides a short   textual description of the status.  The status code is intended for   use by automata, and the status message is intended for the human end   user.  Since the status message is an OPTIONAL component of the   operation response, an IPP application (i.e., a browser, GUI, print   driver or gateway) is NOT REQUIRED to examine or display the status   message, since it MAY not be returned to the application.   The prefix of the status keyword defines the class of response as   follows:      "informational" - Request received, continuing process      "successful" - The action was successfully received, understood,         and accepted      "redirection" - Further action must be taken in order to complete         the request      "client-error" - The request contains bad syntax or cannot be         fulfilled      "server-error" - The IPP object  failed to fulfill an apparently         valid request   As with type2 enums, IPP status codes are extensible.  IPP clients   are NOT REQUIRED to understand the meaning of all registered status   codes, though such understanding is obviously desirable.  However,   IPP clients MUST understand the class of any status code, as   indicated by the prefix, and treat any unrecognized response as being   equivalent to the first status code of that class, with the exception   that an unrecognized response MUST NOT be cached.  For example, if an   unrecognized status code of "client-error-xxx-yyy" is received by the   client, it can safely assume that there was something wrong with its   request and treat the response as if it had received a "client-   error-bad-request" status code.  In such cases, IPP applications   SHOULD present the OPTIONAL message (if present) to the end user   since the message is likely to contain human readable information   which will help to explain the unusual status.  The name of the enum   is the suggested status message for US English.Hastings, et al.            Standards Track                   [Page 177]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The status code values range from 0x0000 to 0x7FFF.  The value ranges   for each status code class are as follows:      "successful" - 0x0000 to 0x00FF      "informational" - 0x0100 to 0x01FF      "redirection" - 0x0200 to 0x02FF      "client-error" - 0x0400 to 0x04FF      "server-error" - 0x0500 to 0x05FF   The top half (128 values) of each range (0x0n40 to 0x0nFF, for n = 0   to 5) is reserved for vendor use within each status code class.   Values 0x0600 to 0x7FFF are reserved for future assignment by IETF   standards track documents and MUST NOT be used.13.1 Status Codes   Each status code is described below.Section 13.1.5.9 contains a   table that indicates which status codes apply to which operations.   The Implementer's Guide [IPP-IIG] describe the suggested steps for   processing IPP attributes for all operations, including returning   status codes.13.1.1 Informational   This class of status code indicates a provisional response and is to   be used for informational purposes only.   There are no status codes defined in IPP/1.1 for this class of status   code.13.1.2 Successful Status Codes   This class of status code indicates that the client's request was   successfully received, understood, and accepted.13.1.2.1 successful-ok (0x0000)   The request has succeeded and no request attributes were substituted   or ignored.  In the case of a response to a create request, the   'successful-ok' status code indicates that the request was   successfully received and validated, and that the Job object has been   created; it does not indicate that the job has been processed.  The   transition of the Job object into the 'completed' state is the only   indicator that the job has been printed.Hastings, et al.            Standards Track                   [Page 178]

RFC 2911              IPP/1.1: Model and Semantics        September 200013.1.2.2 successful-ok-ignored-or-substituted-attributes (0x0001)   The request has succeeded, but some supplied (1) attributes were   ignored or (2) unsupported values were substituted with supported   values or were ignored in order to perform the operation without   rejecting it.  Unsupported attributes, attribute syntaxes, or values   MUST be returned in the Unsupported Attributes group of the response   for all operations.  There is an exception to this rule for the query   operations:  Get-Printer-Attributes, Get-Jobs, and Get-Job-Attributes   for the "requested-attributes" operation attribute only.  When the   supplied values of the "requested-attributes" operation attribute are   requesting attributes that are not supported, the IPP object MAY, but   is NOT REQUIRED to, return the "requested-attributes" attribute in   the Unsupported Attribute response group (with the unsupported values   only).  See sections3.1.7 and3.2.1.2.13.1.2.3 successful-ok-conflicting-attributes (0x0002)   The request has succeeded, but some supplied attribute values   conflicted with the values of other supplied attributes.  These   conflicting values were either (1) substituted with (supported)   values or (2) the attributes were removed in order to process the job   without rejecting it.  Attributes or values which conflict with other   attributes and have been substituted or ignored MUST be returned in   the Unsupported Attributes group of the response for all operations   as supplied by the client.  See sections3.1.7 and3.2.1.2.13.1.3 Redirection Status Codes   This class of status code indicates that further action needs to be   taken to fulfill the request.   There are no status codes defined in IPP/1.1 for this class of status   code.13.1.4 Client Error Status Codes   This class of status code is intended for cases in which the client   seems to have erred.  The IPP object SHOULD return a message   containing an explanation of the error situation and whether it is a   temporary or permanent condition.Hastings, et al.            Standards Track                   [Page 179]

RFC 2911              IPP/1.1: Model and Semantics        September 200013.1.4.1 client-error-bad-request (0x0400)   The request could not be understood by the IPP object due to   malformed syntax (such as the value of a fixed length attribute whose   length does not match the prescribed length for that attribute - see   the Implementer's Guide [IPP-IIG] ).  The IPP application SHOULD NOT   repeat the request without modifications.13.1.4.2 client-error-forbidden (0x0401)   The IPP object understood the request, but is refusing to fulfill it.   Additional authentication information or authorization credentials   will not help and the request SHOULD NOT be repeated.  This status   code is commonly used when the IPP object does not wish to reveal   exactly why the request has been refused or when no other response is   applicable.13.1.4.3 client-error-not-authenticated (0x0402)   The request requires user authentication.  The IPP client may repeat   the request with suitable authentication information. If the request   already included authentication information, then this status code   indicates that authorization has been refused for those credentials.   If this response contains the same challenge as the prior response,   and the user agent has already attempted authentication at least   once, then the response message may contain relevant diagnostic   information.  This status codes reveals more information than   "client-error-forbidden".13.1.4.4 client-error-not-authorized (0x0403)   The requester is not authorized to perform the request.  Additional   authentication information or authorization credentials will not help   and the request SHOULD NOT be repeated.  This status code is used   when the IPP object wishes to reveal that the authentication   information is understandable, however, the requester is explicitly   not authorized to perform the request.  This status codes reveals   more information than "client-error-forbidden" and "client-error-   not-authenticated".13.1.4.5 client-error-not-possible (0x0404)   This status code is used when the request is for something that can   not happen.  For example, there might be a request to cancel a job   that has already been canceled or aborted by the system.  The IPP   client SHOULD NOT repeat the request.Hastings, et al.            Standards Track                   [Page 180]

RFC 2911              IPP/1.1: Model and Semantics        September 200013.1.4.6 client-error-timeout (0x0405)   The client did not produce a request within the time that the IPP   object was prepared to wait.  For example, a client issued a Create-   Job operation and then, after a long period of time, issued a Send-   Document operation and this error status code was returned in   response to the Send-Document request  (seesection 3.3.1).  The IPP   object might have been forced to clean up resources that had been   held for the waiting additional Documents.  The IPP object was forced   to close the Job since the client took too long.  The client SHOULD   NOT repeat the request without modifications.13.1.4.7 client-error-not-found (0x0406)   The IPP object has not found anything matching the request URI.  No   indication is given of whether the condition is temporary or   permanent.  For example, a client with an old reference to a Job (a   URI) tries to cancel the Job, however in the mean time the Job might   have been completed and all record of it at the Printer has been   deleted.  This status code, 'client-error-not-found' is returned   indicating that the referenced Job can not be found.  This error   status code is also used when a client supplies a URI as a reference   to the document data in either a Print-URI or Send-URI operation, but   the document can not be found.   In practice, an IPP application should avoid a not found situation by   first querying and presenting a list of valid Printer URIs and Job   URIs to the end-user.13.1.4.8 client-error-gone (0x0407)   The requested object is no longer available and no forwarding address   is known.  This condition should be considered permanent.  Clients   with link editing capabilities should delete references to the   request URI after user approval.  If the IPP object does not know or   has no facility to determine, whether or not the condition is   permanent, the status code "client-error-not-found" should be used   instead.   This response is primarily intended to assist the task of maintenance   by notifying the recipient that the resource is intentionally   unavailable and that the IPP object administrator desires that remote   links to that resource be removed. It is not necessary to mark all   permanently unavailable resources as "gone" or to keep the mark for   any length of time -- that is left to the discretion of the IPP   object administrator and/or Printer implementation.Hastings, et al.            Standards Track                   [Page 181]

RFC 2911              IPP/1.1: Model and Semantics        September 200013.1.4.9 client-error-request-entity-too-large (0x0408)   The IPP object is refusing to process a request because the request   entity is larger than the IPP object is willing or able to process.   An IPP Printer returns this status code when it limits the size of   print jobs and it receives a print job that exceeds that limit or   when the attributes are so many that their encoding causes the   request entity to exceed IPP object capacity.13.1.4.10 client-error-request-value-too-long (0x0409)   The IPP object is refusing to service the request because one or more   of the client-supplied attributes has a variable length value that is   longer than the maximum length specified for that attribute.  The IPP   object might not have sufficient resources (memory, buffers, etc.) to   process (even temporarily), interpret, and/or ignore a value larger   than the maximum length.  Another use of this error code is when the   IPP object supports the processing of a large value that is less than   the maximum length, but during the processing of the request as a   whole, the object may pass the value onto some other system component   which is not able to accept the large value.  For more details, see   the Implementer's Guide [IPP-IIG] .   Note:  For attribute values that are URIs, this rare condition is   only likely to occur when a client has improperly submitted a request   with long query information (e.g. an IPP application allows an end-   user to enter an invalid URI), when the client has descended into a   URI "black hole" of redirection (e.g., a redirected URI prefix that   points to a suffix of itself), or when the IPP object is under attack   by a client attempting to exploit security holes present in some IPP   objects using fixed-length buffers for reading or manipulating the   Request-URI.13.1.4.11 client-error-document-format-not-supported (0x040A)   The IPP object is refusing to service the request because the   document data is in a format, as specified in the "document-format"   operation attribute, that is not supported by the Printer object.   This error is returned independent of the client-supplied "ipp-   attribute-fidelity".  The Printer object MUST return this status   code, even if there are other Job Template attributes that are not   supported as well, since this error is a bigger problem than with Job   Template attributes.  See sections3.1.6.1,3.1.7, and3.2.1.1.Hastings, et al.            Standards Track                   [Page 182]

RFC 2911              IPP/1.1: Model and Semantics        September 200013.1.4.12 client-error-attributes-or-values-not-supported (0x040B)   In a create request, if the Printer object does not support one or   more attributes, attribute syntaxes, or attribute values supplied in   the request and the client supplied the "ipp-attribute-fidelity"   operation attribute with the 'true' value, the Printer object MUST   return this status code.  The Printer object MUST also return in the   Unsupported Attributes Group all the attributes and/or values   supplied by the client that are not supported.  Seesection 3.1.7.   For example, if the request indicates 'iso-a4' media, but that media   type is not supported by the Printer object.  Or, if the client   supplies a Job Template attribute and the attribute itself is not   even supported by the Printer.  If the "ipp-attribute-fidelity"   attribute is 'false', the Printer MUST ignore or substitute values   for unsupported Job Template attributes and values rather than reject   the request and return this status code.   For any operation where a client requests attributes (such as a Get-   Jobs, Get-Printer-Attributes, or Get-Job-Attributes operation), if   the IPP object does not support one or more of the requested   attributes, the IPP object simply ignores the unsupported requested   attributes and processes the request as if they had not been   supplied, rather than returning this status code.  In this case, the   IPP object MUST return the 'successful-ok-ignored-or-substituted-   attributes' status code and MAY return the unsupported attributes as   values of the "requested-attributes" in the Unsupported Attributes   Group (seesection 13.1.2.2).13.1.4.13 client-error-uri-scheme-not-supported (0x040C)   The scheme of the client-supplied URI in a Print-URI or a Send-URI   operation is not supported.  See sections3.1.6.1 and3.1.7.13.1.4.14 client-error-charset-not-supported (0x040D)   For any operation, if the IPP Printer does not support the charset   supplied by the client in the "attributes-charset" operation   attribute, the Printer MUST reject the operation and return this   status and any 'text' or 'name' attributes using the 'utf-8' charset   (seeSection 3.1.4.1).  See sections3.1.6.1 and  3.1.7.13.1.4.15 client-error-conflicting-attributes (0x040E)   The request is rejected because some attribute values conflicted with   the values of other attributes which this document does not permit to   be substituted or ignored.  The Printer object MUST also return in   the Unsupported Attributes Group the conflicting attributes supplied   by the client.  See sections3.1.7 and3.2.1.2.Hastings, et al.            Standards Track                   [Page 183]

RFC 2911              IPP/1.1: Model and Semantics        September 200013.1.4.16 client-error-compression-not-supported (0x040F)   The IPP object is refusing to service the request because the   document data, as specified in the "compression" operation attribute,   is compressed in a way that is not supported by the Printer object.   This error is returned independent of the client-supplied "ipp-   attribute-fidelity".  The Printer object MUST return this status   code, even if there are other Job Template attributes that are not   supported as well, since this error is a bigger problem than with Job   Template attributes.  See sections3.1.6.1,3.1.7, and3.2.1.1.13.1.4.17 client-error-compression-error (0x0410)   The IPP object is refusing to service the request because the   document data cannot be decompressed when using the algorithm   specified by the "compression" operation attribute.  This error is   returned independent of the client-supplied "ipp-attribute-fidelity".   The Printer object MUST return this status code, even if there are   Job Template attributes that are not supported as well, since this   error is a bigger problem than with Job Template attributes.  See   sections3.1.7 and3.2.1.1.13.1.4.18 client-error-document-format-error (0x0411)   The IPP object is refusing to service the request because Printer   encountered an error in the document data while interpreting it.   This error is returned independent of the client-supplied "ipp-   attribute-fidelity".  The Printer object MUST return this status   code, even if there are Job Template attributes that are not   supported as well, since this error is a bigger problem than with Job   Template attributes.  See sections3.1.7 and3.2.1.1.13.1.4.19 client-error-document-access-error (0x0412)   The IPP object is refusing to service the Print-URI or Send-URI   request because Printer encountered an access error while attempting   to validate the accessibility or access the document data specified   in the "document-uri" operation attribute.  The Printer MAY also   return a specific document access error code using the "document-   access-error" operation attribute (seesection 3.1.6.4).  This error   is returned independent of the client-supplied "ipp-attribute-   fidelity".  The Printer object MUST return this status code, even if   there are Job Template attributes that are not supported as well,   since this error is a bigger problem than with Job Template   attributes.  See sections3.1.6.1 and3.1.7.Hastings, et al.            Standards Track                   [Page 184]

RFC 2911              IPP/1.1: Model and Semantics        September 200013.1.5 Server Error Status Codes   This class of status codes indicates cases in which the IPP object is   aware that it has erred or is incapable of performing the request.   The IPP object SHOULD include a message containing an explanation of   the error situation, and whether it is a temporary or permanent   condition.13.1.5.1 server-error-internal-error (0x0500)   The IPP object encountered an unexpected condition that prevented it   from fulfilling the request.  This error status code differs from   "server-error-temporary-error" in that it implies a more permanent   type of internal error.  It also differs from "server-error-device-   error" in that it implies an unexpected condition (unlike a paper-jam   or out-of-toner problem which is undesirable but expected).  This   error status code indicates that probably some knowledgeable human   intervention is required.13.1.5.2 server-error-operation-not-supported (0x0501)   The IPP object does not support the functionality required to fulfill   the request. This is the appropriate response when the IPP object   does not recognize an operation or is not capable of supporting it.   See sections3.1.6.1 and3.1.7.13.1.5.3 server-error-service-unavailable (0x0502)   The IPP object is currently unable to handle the request due to a   temporary overloading or maintenance of the IPP object.  The   implication is that this is a temporary condition which will be   alleviated after some delay. If known, the length of the delay may be   indicated in the message.  If no delay is given, the IPP application   should handle the response as it would for a "server-error-   temporary-error" response.  If the condition is more permanent, the   error status codes "client-error-gone" or "client-error-not-found"   could be used.13.1.5.4 server-error-version-not-supported (0x0503)   The IPP object does not support, or refuses to support, the IPP   protocol version that was supplied as the value of the "version-   number" operation parameter in the request.  The IPP object is   indicating that it is unable or unwilling to complete the request   using the same major and minor version number as supplied in the   request other than with this error message. The error response SHOULD   contain a "status-message" attribute (seesection 3.1.6.2) describingHastings, et al.            Standards Track                   [Page 185]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   why that version is not supported and what other versions are   supported by that IPP object.  See sections3.1.6.1,3.1.7, and   3.1.8.   The error response MUST identify in the "version-number" operation   parameter the closest version number that the IPP object does   support.  For example, if a client supplies version '1.0' and an   IPP/1.1 object supports version '1.0', then it responds with version   '1.0' in all responses to such a request.  If the IPP/1.1 object does   not support version '1.0', then it should accept the request and   respond with version '1.1' or may reject the request and respond with   this error code and version   '1.1'.  If a client supplies a version '1.2', the IPP/1.1 object   should accept the request and return version '1.1' or may reject the   request and respond with this error code and version '1.1'.  See   sections3.1.8 and4.4.14.13.1.5.5 server-error-device-error (0x0504)   A printer error, such as a paper jam, occurs while the IPP object   processes a Print or Send operation.  The response contains the true   Job Status (the values of the "job-state" and "job-state-reasons"   attributes).  Additional information can be returned in the OPTIONAL   "job-state-message" attribute value or in the OPTIONAL status message   that describes the error in more detail.  This error status code is   only returned in situations where the Printer is unable to accept the   create request because of such a device error.  For example, if the   Printer is unable to spool, and can only accept one job at a time,   the reason it might reject a create request is that the printer   currently has a paper jam.  In many cases however, where the Printer   object can accept the request even though the Printer has some error   condition, the 'successful-ok' status code will be returned.  In such   a case, the client would look at the returned Job Object Attributes   or later query the Printer to determine its state and state reasons.13.1.5.6 server-error-temporary-error (0x0505)   A temporary error such as a buffer full write error, a memory   overflow (i.e. the document data exceeds the memory of the Printer),   or a disk full condition, occurs while the IPP Printer processes an   operation.  The client MAY try the unmodified request again at some   later point in time with an expectation that the temporary internal   error condition may have been cleared.  Alternatively, as an   implementation option, a Printer object MAY delay the response until   the temporary condition is cleared so that no error is returned.Hastings, et al.            Standards Track                   [Page 186]

RFC 2911              IPP/1.1: Model and Semantics        September 200013.1.5.7 server-error-not-accepting-jobs (0x0506)   A temporary error indicating that the Printer is not currently   accepting jobs, because the administrator has set the value of the   Printer's "printer-is-accepting-jobs" attribute to 'false' (by means   outside the scope of this IPP/1.1 document).13.1.5.8 server-error-busy (0x0507)   A temporary error indicating that the Printer is too busy processing   jobs and/or other requests. The client SHOULD try the unmodified   request again at some later point in time with an expectation that   the temporary busy condition will have been cleared.13.1.5.9 server-error-job-canceled (0x0508)   An error indicating that the job has been canceled by an operator or   the system while the client was transmitting the data to the IPP   Printer.  If a job-id and job-uri had been created, then they are   returned in the Print-Job, Send-Document, or Send-URI response as   usual; otherwise, no job-id and job-uri are returned in the response.13.1.5.10 server-error-multiple-document-jobs-not-supported (0x0509)   The IPP object does not support multiple documents per job and a   client attempted to supply document data with a second Send-Document   or Send-URI operation.13.2 Status Codes for IPP Operations   PJ = Print-Job, PU = Print-URI, CJ = Create-Job, SD = Send-Document   SU = Send-URI, V = Validate-Job, GA = Get-Job-Attributes and   Get-Printer-Attributes, GJ = Get-Jobs, C = Cancel-JobHastings, et al.            Standards Track                   [Page 187]

RFC 2911              IPP/1.1: Model and Semantics        September 2000                                                  IPP Operations   IPP Status Keyword                       PJ PU CJ SD SU V GA GJ C   ------------------                       -- -- -- -- -- - -- -- -   successful-ok                            x  x  x  x  x  x x  x  x   successful-ok-ignored-or-substituted-    x  x  x  x  x  x x  x  x        attributes   successful-ok-conflicting-attributes     x  x  x  x  x  x x  x  x   client-error-bad-request                 x  x  x  x  x  x x  x  x   client-error-forbidden                   x  x  x  x  x  x x  x  x   client-error-not-authenticated           x  x  x  x  x  x x  x  x   client-error-not-authorized              x  x  x  x  x  x x  x  x   client-error-not-possible                x  x  x  x  x  x x  x  x   client-error-timeout                              x  x   client-error-not-found                   x  x  x  x  x  x x  x  x   client-error-gone                        x  x  x  x  x  x x  x  x   client-error-request-entity-too-large    x  x  x  x  x  x x  x  x   client-error-request-value-too-long      x  x  x  x  x  x x  x  x   client-error-document-format-not-        x  x     x  x  x x        supported   client-error-attributes-or-values-not-   x  x  x  x  x  x x  x  x        supported   client-error-uri-scheme-not-supported       x        x   client-error-charset-not-supported       x  x  x  x  x  x x  x  x   client-error-conflicting-attributes      x  x  x  x  x  x x  x  x   client-error-compression-not-supported   x  x     x  x  x   client-error-compression-error           x  x     x  x   client-error-document-format-error       x  x     x  x   client-error-document-access-error          x        x   server-error-internal-error              x  x  x  x  x  x x  x  x   server-error-operation-not-supported        x  x  x  x   server-error-service-unavailable         x  x  x  x  x  x x  x  x   server-error-version-not-supported       x  x  x  x  x  x x  x  x   server-error-device-error                x  x  x  x  x   server-error-temporary-error             x  x  x  x  x   server-error-not-accepting-jobs          x  x  x        x   server-error-busy                        x  x  x  x  x  x x  x  x   server-error-job-canceled                x        x  x   server-error-multiple-document-jobs-              x  x          not-supported   HJ = Hold-Job, RJ = Release-Job, RS = Restart-Job   PP = Pause-Printer, RP = Resume-Printer, PJ = Purge-JobsHastings, et al.            Standards Track                   [Page 188]

RFC 2911              IPP/1.1: Model and Semantics        September 2000                                            IPP Operations (cont.)   IPP Status Keyword                       HJ RJ RS PP RP PJ   ------------------                       -- -- -- -- -- --   successful-ok                            x  x  x  x  x  x   successful-ok-ignored-or-substituted-    x  x  x  x  x  x        attributes   successful-ok-conflicting-attributes     x  x  x  x  x  x   client-error-bad-request                 x  x  x  x  x  x   client-error-forbidden                   x  x  x  x  x  x   client-error-not-authenticated           x  x  x  x  x  x   client-error-not-authorized              x  x  x  x  x  x   client-error-not-possible                x  x  x  x  x  x   client-error-timeout   client-error-not-found                   x  x  x  x  x  x   client-error-gone                        x  x  x  x  x  x   client-error-request-entity-too-large    x  x  x  x  x  x   client-error-request-value-too-long      x  x  x  x  x  x   client-error-document-format-not-        supported   client-error-attributes-or-values-not-   x  x  x  x  x  x        supported   client-error-uri-scheme-not-supported   client-error-charset-not-supported       x  x  x  x  x  x   client-error-conflicting-attributes      x  x  x  x  x  x   client-error-compression-not-supported   client-error-compression-error   client-error-document-format-error   client-error-document-access-error   server-error-internal-error              x  x  x  x  x  x   server-error-operation-not-supported     x  x  x  x  x  x   server-error-service-unavailable         x  x  x  x  x  x   server-error-version-not-supported       x  x  x  x  x  x   server-error-device-error   server-error-temporary-error             x  x  x  x  x  x   server-error-not-accepting-jobs   server-error-busy                        x  x  x  x  x  x   server-error-job-canceled   server-error-multiple-document-jobs-          not-supportedHastings, et al.            Standards Track                   [Page 189]

RFC 2911              IPP/1.1: Model and Semantics        September 200014.  APPENDIX C:"media" keyword values   Standard keyword values are taken from several sources.   Standard values are defined (taken from DPA[ISO10175] and the Printer   MIB[RFC1759]):    'default': The default medium for the output device    'iso-a4-white': Specifies the ISO A4 white medium: 210 mm x 297 mm    'iso-a4-colored': Specifies the ISO A4 colored medium: 210 mm x 297       mm    'iso-a4-transparent' Specifies the ISO A4 transparent medium: 210 mm       x 297 mm    'iso-a3-white': Specifies the ISO A3 white medium: 297 mm x 420 mm    'iso-a3-colored': Specifies the ISO A3 colored medium: 297 mm x 420       mm    'iso-a5-white': Specifies the ISO A5 white medium: 148 mm x 210 mm    'iso-a5-colored': Specifies the ISO A5 colored medium: 148 mm x 210       mm    'iso-b4-white': Specifies the ISO B4 white medium: 250 mm x 353 mm    'iso-b4-colored': Specifies the ISO B4 colored medium: 250 mm x 353       mm    'iso-b5-white': Specifies the ISO B5 white medium: 176 mm x 250 mm    'iso-b5-colored': Specifies the ISO B5 colored medium: 176 mm x 250       mm    'jis-b4-white': Specifies the JIS B4 white medium: 257 mm x 364 mm    'jis-b4-colored': Specifies the JIS B4 colored medium: 257 mm x 364       mm    'jis-b5-white': Specifies the JIS B5 white medium: 182 mm x 257 mm    'jis-b5-colored': Specifies the JIS B5 colored medium: 182 mm x 257       mm   The following standard values are defined for North American media:    'na-letter-white': Specifies the North American letter white medium    'na-letter-colored': Specifies the North American letter colored       medium    'na-letter-transparent': Specifies the North American letter       transparent medium    'na-legal-white': Specifies the North American legal white medium    'na-legal-colored': Specifies the North American legal colored       mediumHastings, et al.            Standards Track                   [Page 190]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The following standard values are defined for envelopes:    'iso-b4-envelope': Specifies the ISO B4 envelope medium    'iso-b5-envelope': Specifies the ISO B5 envelope medium    'iso-c3-envelope': Specifies the ISO C3 envelope medium    'iso-c4-envelope': Specifies the ISO C4 envelope medium    'iso-c5-envelope': Specifies the ISO C5 envelope medium    'iso-c6-envelope': Specifies the ISO C6 envelope medium    'iso-designated-long-envelope': Specifies the ISO Designated Long       envelope medium    'na-10x13-envelope': Specifies the North American 10x13 envelope       medium    'na-9x12-envelope': Specifies the North American 9x12 envelope       medium    'monarch-envelope': Specifies the Monarch envelope    'na-number-10-envelope': Specifies the North American number 10       business envelope medium    'na-7x9-envelope': Specifies the North American 7x9 inch envelope    'na-9x11-envelope': Specifies the North American 9x11 inch       envelope    'na-10x14-envelope': Specifies the North American 10x14 inch       envelope    'na-number-9-envelope': Specifies the North American number 9       business envelope    'na-6x9-envelope': Specifies the North American 6x9 inch envelope    'na-10x15-envelope': Specifies the North American 10x15 inch       envelope   The following standard values are defined for the less commonly used   media: 'executive-white': Specifies the white executive medium 'folio-white': Specifies the folio white medium 'invoice-white': Specifies the white invoice medium 'ledger-white': Specifies the white ledger medium 'quarto-white': Specified the white quarto medium 'iso-a0-white': Specifies the ISO A0 white medium: 841 mm x 1189 mm 'iso-a0-transparent': Specifies the ISO A0 transparent medium: 841 mm    x 1189 mm 'iso-a0-translucent': Specifies the ISO A0 translucent medium: 841 mm    x 1189 mm 'iso-a1-white': Specifies the ISO A1 white medium: 594 mm x 841 mm 'iso-a1-transparent': Specifies the ISO A1 transparent medium: 594 mm    x 841 mm 'iso-a1-translucent': Specifies the ISO A1 translucent medium: 594 mm    x 841 mm 'iso-a2-white': Specifies the ISO A2 white medium: 420 mm x 594 mmHastings, et al.            Standards Track                   [Page 191]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'iso-a2-transparent': Specifies the ISO A2 transparent medium: 420 mm    x 594 mm 'iso-a2-translucent': Specifies the ISO A2 translucent medium: 420 mm    x 594 mm 'iso-a3-transparent': Specifies the ISO A3 transparent medium: 297 mm    x 420 mm 'iso-a3-translucent': Specifies the ISO A3 translucent medium: 297 mm    x 420 mm 'iso-a4-translucent': Specifies the ISO A4 translucent medium: 210 mm    x 297 mm 'iso-a5-transparent': Specifies the ISO A5 transparent medium: 148 mm    x 210 mm 'iso-a5-translucent': Specifies the ISO A5 translucent medium: 148 mm    x 210 mm 'iso-a6-white': Specifies the ISO A6 white medium: 105 mm x 148 mm 'iso-a7-white': Specifies the ISO A7 white medium: 74 mm x 105 mm 'iso-a8-white': Specifies the ISO A8 white medium: 52 mm x 74 mm 'iso-a9-white': Specifies the ISO A9 white medium: 37 mm x 52 mm 'iso-a10-white': Specifies the ISO A10 white medium: 26 mm x 37 mm 'iso-b0-white': Specifies the ISO B0 white medium: 1000 mm x 1414 mm 'iso-b1-white': Specifies the ISO B1 white medium: 707 mm x 1000 mm 'iso-b2-white': Specifies the ISO B2 white medium: 500 mm x 707 mm 'iso-b3-white': Specifies the ISO B3 white medium: 353 mm x 500 mm 'iso-b6-white': Specifies the ISO B6 white medium: 125 mm x 176 mm 'iso-b7-white': Specifies the ISO B7 white medium: 88 mm x 125 mm 'iso-b8-white': Specifies the ISO B8 white medium: 62 mm x 88 mm 'iso-b9-white': Specifies the ISO B9 white medium: 44 mm x 62 mm 'iso-b10-white': Specifies the ISO B10 white medium: 31 mm x 44 mm 'jis-b0-white': Specifies the JIS B0 white medium: 1030 mm x 1456 mm 'jis-b0-transparent': Specifies the JIS B0 transparent medium: 1030    mm x 1456 mm 'jis-b0-translucent': Specifies the JIS B0 translucent medium: 1030    mm x 1456 mm 'jis-b1-white': Specifies the JIS B1 white medium: 728 mm x 1030 mm 'jis-b1-transparent': Specifies the JIS B1 transparent medium: 728 mm    x 1030 mm 'jis-b1-translucent': Specifies the JIS B1 translucent medium: 728 mm    x 1030 mm 'jis-b2-white': Specifies the JIS B2 white medium: 515 mm x 728 mm 'jis-b2-transparent': Specifies the JIS B2 transparent medium: 515 mm    x 728 mm 'jis-b2-translucent': Specifies the JIS B2 translucent medium: 515 mm    x 728 mm 'jis-b3-white': Specifies the JIS B3 white medium: 364 mm x 515 mm 'jis-b3-transparent': Specifies the JIS B3 transparent medium: 364 mm    x 515 mm 'jis-b3-translucent': Specifies the JIS B3 translucent medium: 364 mm    x 515 mmHastings, et al.            Standards Track                   [Page 192]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'jis-b4-transparent': Specifies the JIS B4 transparent medium: 257 mm    x 364 mm 'jis-b4-translucent': Specifies the JIS B4 translucent medium: 257 mm    x 364 mm 'jis-b5-transparent': Specifies the JIS B5 transparent medium: 182 mm    x 257 mm 'jis-b5-translucent': Specifies the JIS B5 translucent medium: 182 mm    x 257 mm 'jis-b6-white': Specifies the JIS B6 white medium: 128 mm x 182 mm 'jis-b7-white': Specifies the JIS B7 white medium: 91 mm x 128 mm 'jis-b8-white': Specifies the JIS B8 white medium: 64 mm x 91 mm 'jis-b9-white': Specifies the JIS B9 white medium: 45 mm x 64 mm 'jis-b10-white': Specifies the JIS B10 white medium: 32 mm x 45 mm   The following standard values are defined for American Standard (i.e.   ANSI) engineering media:    'a-white': Specifies the engineering ANSI A size white medium: 8.5       inches x 11 inches    'a-transparent': Specifies the engineering ANSI A size transparent       medium: 8.5 inches x 11 inches    'a-translucent': Specifies the engineering ANSI A size translucent       medium: 8.5 inches x 11 inches    'b-white': Specifies the engineering ANSI B size white medium: 11       inches x 17 inches    'b-transparent': Specifies the engineering ANSI B size transparent       medium: 11 inches x 17 inches)    'b-translucent': Specifies the engineering ANSI B size translucent       medium: 11 inches x 17 inches    'c-white': Specifies the engineering ANSI C size white medium: 17       inches x 22 inches    'c-transparent': Specifies the engineering ANSI C size transparent       medium: 17 inches x 22 inches    'c-translucent': Specifies the engineering ANSI C size translucent       medium: 17 inches x 22 inches    'd-white': Specifies the engineering ANSI D size white medium: 22       inches x 34 inches    'd-transparent': Specifies the engineering ANSI D size transparent       medium: 22 inches x 34 inches    'd-translucent': Specifies the engineering ANSI D size translucent       medium: 22 inches x 34 inches    'e-white': Specifies the engineering ANSI E size white medium: 34       inches x 44 inches    'e-transparent': Specifies the engineering ANSI E size transparent       medium: 34 inches x 44 inches    'e-translucent': Specifies the engineering ANSI E size translucent       medium: 34 inches x 44 inchesHastings, et al.            Standards Track                   [Page 193]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The following standard values are defined for American Standard (i.e.   ANSI) engineering media for devices that provide the "synchro-cut"   feature (seesection 14.1): 'axsynchro-white': Specifies the roll paper having the width of the    longer edge (11 inches) of the engineering ANSI A size white medium    and cuts synchronizing with data. 'axsynchro-transparent': Specifies the roll paper having the width of    the longer edge (11 inches) of the engineering ANSI A size    transparent medium and cuts synchronizing with data. 'axsynchro-translucent': Specifies the roll paper having the width of    the longer edge (11 inches) of the engineering ANSI A size    translucent medium and cuts synchronizing with data. 'bxsynchro-white': Specifies the roll paper having the width of the    longer edge (17 inches) of the engineering ANSI B size white medium    and cuts synchronizing with data. 'bxsynchro-transparent': Specifies the roll paper having the width of    the longer edge (17 inches) of the engineering ANSI B size    transparent medium and cuts synchronizing with data. 'bxsynchro-translucent': Specifies the roll paper having the width of    the longer edge (17 inches) of the engineering ANSI B size    translucent medium and cuts synchronizing with data. 'cxsynchro-white': Specifies the roll paper having the width of the    longer edge (22 inches) of the engineering ANSI C size white medium    and cuts synchronizing with data. 'cxsynchro-transparent': Specifies the roll paper having the width of    the longer edge (22 inches) of the engineering ANSI C size    transparent medium and cuts synchronizing with data. 'cxsynchro-translucent': Specifies the roll paper having the width of    the longer edge (22 inches) of the engineering ANSI C size    translucent medium and cuts synchronizing with data. 'dxsynchro-white': Specifies the roll paper having the width of the    longer edge (34 inches) of the engineering ANSI D size white medium    and cuts synchronizing with data. 'dxsynchro-transparent': Specifies the roll paper having the width of    the longer edge (34 inches) of the engineering ANSI D size    transparent medium and cuts synchronizing with data. 'dxsynchro-translucent': Specifies the roll paper having the width of    the longer edge (34 inches) of the engineering ANSI D size    translucent medium and cuts synchronizing with data. 'exsynchro-white': Specifies the roll paper having the width of the    longer edge (44 inches) of the engineering ANSI E size white medium    and cuts synchronizing with data. 'exsynchro-transparent': Specifies the roll paper having the width of    the longer edge (44 inches) of the engineering ANSI E size    transparent medium and cuts synchronizing with data.Hastings, et al.            Standards Track                   [Page 194]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'exsynchro-translucent': Specifies the roll paper having the width of    the longer edge (44 inches) of the engineering ANSI E size    translucent medium and cuts synchronizing with data.   The following standard values are defined for American Architectural   engineering media: 'arch-a-white': Specifies the Architectural A size white medium: 9    inches x 12 inches 'arch-a-transparent': Specifies the Architectural A size transparent    medium: 9 inches x 12 inches 'arch-a-translucent': Specifies the Architectural A size translucent    medium: 9 inches x 12 inches 'arch-b-white': Specifies the Architectural B size white medium: 12    inches x 18 inches 'arch-b-transparent': Specifies the Architectural B size transparent    medium: 12 inches x 18 inches 'arch-b-translucent': Specifies the Architectural B size translucent    medium: 12 inches x 18 inches 'arch-c-white': Specifies the Architectural C size white medium: 18    inches x 24 inches 'arch-c-transparent': Specifies the Architectural C size transparent    medium: 18 inches x 24 inches 'arch-c-translucent': Specifies the Architectural C size translucent    medium: 18 inches x 24 inches 'arch-d-white': Specifies the Architectural D size white medium: 24    inches x 36 inches 'arch-d-transparent': Specifies the Architectural D size transparent    medium: 24 inches x 36 inches 'arch-d-translucent': Specifies the Architectural D size translucent    medium: 24 inches x 36 inches 'arch-e-white': Specifies the Architectural E size white medium: 36    inches x 48 inches 'arch-e-transparent': Specifies the Architectural E size transparent    medium: 36 inches x 48 inches 'arch-e-translucent': Specifies the Architectural E size translucent    medium: 36 inches x 48 inches   The following standard values are defined for American Architectural   engineering media for devices that provide the "synchro-cut" feature   (seesection 14.1): 'arch-axsynchro-white': Specifies the roll paper having the width of    the longer edge (12 inches) of the Architectural A size white    medium and cuts synchronizing with data. 'arch-axsynchro-transparent': Specifies the roll paper having the    width of the longer edge (12 inches) of the Architectural A size    transparent medium and cuts synchronizing with data.Hastings, et al.            Standards Track                   [Page 195]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'arch-axsynchro-translucent': Specifies the roll paper having the    width of the longer edge (12 inches) of the Architectural A size    translucent medium and cuts synchronizing with data. 'arch-bxsynchro-white': Specifies the roll paper having the width of    the longer edge (18 inches) of the Architectural B size white    medium and cuts synchronizing with data. 'arch-bxsynchro-transparent': Specifies the roll paper having the    width of the longer edge (18 inches) of the Architectural B size    transparent medium and cuts synchronizing with data. 'arch-bxsynchro-translucent': Specifies the roll paper having the    width of the longer edge (18 inches) of the Architectural B size    translucent medium and cuts synchronizing with data. 'arch-cxsynchro-white': Specifies the roll paper having the width of    the longer edge (24 inches) of the Architectural C size white    medium and cuts synchronizing with data. 'arch-cxsynchro-transparent': Specifies the roll paper having the    width of the longer edge (24 inches) of the Architectural C size    transparent medium and cuts synchronizing with data. 'arch-cxsynchro-translucent': Specifies the roll paper having the    width of the longer edge (24 inches) of the Architectural C size    translucent medium and cuts synchronizing with data. 'arch-dxsynchro-white': Specifies the roll paper having the width of    the longer edge (36 inches) of the Architectural D size white    medium and cuts synchronizing with data. 'arch-dxsynchro-transparent': Specifies the roll paper having the    width of the longer edge (36 inches) of the Architectural D size    transparent medium and cuts synchronizing with data. 'arch-dxsynchro-translucent': Specifies the roll paper having the    width of the longer edge (36 inches) of the Architectural D size    translucent medium and cuts synchronizing with data. 'arch-exsynchro-white': Specifies the roll paper having the width of    the longer edge (48 inches) of the Architectural E size white    medium and cuts synchronizing with data. 'arch-exsynchro-transparent': Specifies the roll paper having the    width of the longer edge (48 inches) of the Architectural E size    transparent medium and cuts synchronizing with data. 'arch-exsynchro-translucent': Specifies the roll paper having the    width of the longer edge (48 inches) of the Architectural E size    translucent medium and cuts synchronizing with data.   The following standard values are defined for Japanese and European   Standard (i.e. ISO) engineering media, which are of a long fixed size   [ASME-Y14.1M]: 'iso-a1x3-white': Specifies the ISO A1X3 white medium having the      width of the longer edge (841 mm) of the ISO A1 mediumHastings, et al.            Standards Track                   [Page 196]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'iso-a1x3-transparent': Specifies the ISO A1X3 transparent medium      having the width of the longer edge (841 mm) of the ISO A1      medium 'iso-a1x3-translucent': Specifies the ISO A1X3 translucent medium      having the width of the longer edge (841 mm) of the ISO A1      medium 'iso-a1x4-white': Specifies the ISO A1X4 white medium having the      width of the longer edge (841 mm) of the ISO A1 medium 'iso-a1x4-transparent': Specifies the ISO A1X4 transparent medium      having the width of the longer edge (841 mm) of the ISO A1      medium 'iso-a1x4- translucent': Specifies the ISO A1X4 translucent medium      having the width of the longer edge (841 mm) of the ISO A1      medium 'iso-a2x3-white': Specifies the ISO A2X3 white medium having the      width of the longer edge (594 mm) of the ISO A2 medium 'iso-a2x3-transparent': Specifies the ISO A2X3 transparent medium      having the width of the longer edge (594 mm) of the ISO A2      medium 'iso-a2x3-translucent': Specifies the ISO A2X3 translucent medium      having the width of the longer edge (594 mm) of the ISO A2      medium 'iso-a2x4-white': Specifies the ISO A2X4 white medium having the      width of the longer edge (594 mm) of the ISO A2 medium 'iso-a2x4-transparent': Specifies the ISO A2X4 transparent medium      having the width of the longer edge (594 mm) of the ISO A2      medium 'iso-a2x4-translucent': Specifies the ISO A2X4 translucent medium      having the width of the longer edge (594 mm) of the ISO A2      medium 'iso-a2x5-white': Specifies the ISO A2X5 white medium having the      width of the longer edge (594 mm) of the ISO A2 medium 'iso-a2x5-transparent': Specifies the ISO A2X5 transparent medium      having the width of the longer edge (594 mm) of the ISO A2      medium 'iso-a2x5-translucent': Specifies the ISO A2X5 translucent medium      having the width of the longer edge (594 mm) of the ISO A2      medium 'iso-a3x3-white': Specifies the ISO A3X3 white medium having the      width of the longer edge (420 mm) of the ISO A3 medium 'iso-a3x3-transparent': Specifies the ISO A3X3 transparent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x3-translucent': Specifies the ISO A3X3 translucent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x4-white': Specifies the ISO A3X4 white medium having the      width of the longer edge (420 mm) of the ISO A3 mediumHastings, et al.            Standards Track                   [Page 197]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'iso-a3x4-transparent': Specifies the ISO A3X4 transparent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x4-translucent': Specifies the ISO A3X4 translucent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x5-white': Specifies the ISO A3X5 white medium having the      width of the longer edge (420 mm) of the ISO A3 medium 'iso-a3x5-transparent': Specifies the ISO A3X5 transparent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x5-translucent': Specifies the ISO A3X5 translucent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x6-white': Specifies the ISO A3X6 white medium having the      width of the longer edge (420 mm) of the ISO A3 medium 'iso-a3x6-transparent': Specifies the ISO A3X6 transparent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x6-translucent': Specifies the ISO A3X6 translucent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x7-white': Specifies the ISO A3X7 white medium having the      width of the longer edge (420 mm) of the ISO A3 medium 'iso-a3x7-transparent': Specifies the ISO A3X7 transparent medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a3x7-translucent'': Specifies the ISO A3X7 translucent' medium      having the width of the longer edge (420 mm) of the ISO A3      medium 'iso-a4x3-white': Specifies the ISO A4X3 white medium having the      width of the longer edge (297 mm) of the ISO A4 medium 'iso-a4x3-transparent': Specifies the ISO A4X3 transparent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x3-translucent'': Specifies the ISO A4X3 translucent' medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x4-white': Specifies the ISO A4X4 white medium having the      width of the longer edge (297 mm) of the ISO A4 medium 'iso-a4x4-transparent': Specifies the ISO A4X4 transparent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x4-translucent': Specifies the ISO A4X4 translucent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x5-white': Specifies the ISO A4X5 white medium having the      width of the longer edge (297 mm) of the ISO A4 mediumHastings, et al.            Standards Track                   [Page 198]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'iso-a4x5-transparent': Specifies the ISO A4X5 transparent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x5-translucent': Specifies the ISO A4X5 translucent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x6-white': Specifies the ISO A4X6 white medium having the      width of the longer edge (297 mm) of the ISO A4 medium 'iso-a4x6-transparent': Specifies the ISO A4X6 transparent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x6-translucent': Specifies the ISO A4X6 translucent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x7-white': Specifies the ISO A4X7 white medium having the      width of the longer edge (297 mm) of the ISO A4 medium 'iso-a4x7-transparent': Specifies the ISO A4X7 transparent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x7-translucent': Specifies the ISO A4X7 translucent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x8-white': Specifies the ISO A4X8 white medium having the      width of the longer edge (297 mm) of the ISO A4 medium 'iso-a4x8-transparent': Specifies the ISO A4X8 transparent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x8-translucent': Specifies the ISO A4X8 translucent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x9-white': Specifies the ISO A4X9 white medium having the      width of the longer edge (297 mm) of the ISO A4 medium 'iso-a4x9-transparent': Specifies the ISO A4X9 transparent medium      having the width of the longer edge (297 mm) of the ISO A4      medium 'iso-a4x9-translucent': Specifies the ISO A4X9 translucent medium      having the width of the longer edge (297 mm) of the ISO A4      medium   The following standard values are defined for Japanese and European   Standard (i.e. ISO) engineering media, which are either a long fixed   size [ASME-Y14.1M] or roll feed, for devices that provide the   "synchro-cut" feature (seesection 14.1): 'iso-a0xsynchro-white': Specifies the paper having the width of the      longer edge (1189 mm) of the ISO A0 white medium and cuts      synchronizing with data.Hastings, et al.            Standards Track                   [Page 199]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'iso-a0xsynchro-transparent': Specifies the paper having the width of      the longer edge (1189 mm) of the ISO A0 transparent medium and      cuts synchronizing with data. 'iso-a0xsynchro-translucent': Specifies the paper having the width of      the longer edge (1189 mm) of the ISO A0 translucent medium and      cuts synchronizing with data. 'iso-a1xsynchro-white': Specifies the paper having the width of the      longer edge (841 mm) of the ISO A1 white medium and cuts      synchronizing with data. 'iso-a1xsynchro-transparent': Specifies the paper having the width of      the longer edge (841 mm) of the ISO A1 transparent medium and      cuts synchronizing with data. 'iso-a1xsynchro-translucent': Specifies the paper having the width of      the longer edge (841 mm) of the ISO A1 translucent medium and      cuts synchronizing with data. 'iso-a2xsynchro-white': Specifies the paper having the width of the      longer edge (594 mm) of the ISO A2 white medium and cuts      synchronizing with data. 'iso-a2xsynchro-transparent': Specifies the paper having the width of      the longer edge (594 mm) of the ISO A2 transparent medium and      cuts synchronizing with data. 'iso-a2xsynchro-translucent': Specifies the paper having the width of      the longer edge (594 mm) of the ISO A2 translucent medium and      cuts synchronizing with data. 'iso-a3xsynchro-white': Specifies the paper having the width of the      longer edge (420 mm) of the ISO A3 white medium and cuts      synchronizing with data. 'iso-a3xsynchro-transparent': Specifies the paper having the width of      the longer edge (420 mm) of the ISO A3 transparent medium and      cuts synchronizing with data. 'iso-a3xsynchro-translucent': Specifies the paper having the width of      the longer edge (420 mm) of the ISO A3 translucent medium and      cuts synchronizing with data. 'iso-a4xsynchro-white': Specifies the paper having the width of the      longer edge (297 mm) of the ISO A4 white medium and cuts      synchronizing with data. 'iso-a4xsynchro-transparent': Specifies the paper having the width of      the longer edge (297 mm) of the ISO A4 transparent medium and      cuts synchronizing with data. 'iso-a4xsynchro-translucent': Specifies the paper having the width of      the longer edge (297 mm) of the ISO A4 transparent medium and      cuts synchronizing with data.   The following standard values are defined for American Standard (i.e.   ANSI) engineering media, American Architectural engineering media,   and Japanese and European Standard (i.e. ISO) engineering media,Hastings, et al.            Standards Track                   [Page 200]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   which are either a long fixed size [ASME-Y14.1M] or roll feed, for   devices that provide the "synchro-cut" feature and/or the "auto-   select" feature (seesection 14.1): 'auto-white': Specifies that the printer selects the white medium      with the appropriate fixed size (e.g. a1, a2, etc.) or data-      synchro size, and the selection is implementation-defined. 'auto-transparent': Specifies that the printer selects the      transparent medium with the appropriate fixed size (e.g. a1, a2,      etc.) or data-synchro size, and the selection is implementation-      defined. 'auto-translucent': Specifies that the printer selects the      translucent medium with the appropriate fixed size (e.g. a1, a2,      etc.) or data-synchro size, and the selection is implementation-      defined. 'auto-fixed-size-white': Specifies that the printer selects the white      medium with the appropriate fixed size (e.g. a1, a2, etc.) or      the appropriate long fixed size listed above. 'auto-fixed-size-transparent': Specifies that the printer selects the      transparent medium with the appropriate fixed size (e.g. a1, a2,      etc.) or the appropriate long fixed size listed above. 'auto-fixed-size-translucent': Specifies that the printer selects the      translucent medium with the appropriate fixed size (e.g. a1, a2,      etc.) or the appropriate long fixed size listed above. 'auto-synchro-white': Specifies that the printer selects the white      paper with the appropriate width and cuts it synchronizing with      data. 'auto-synchro-transparent': Specifies that the printer selects the      transparent paper with the appropriate width and cuts it      synchronizing with data. 'auto-synchro-translucent': Specifies that the printer selects the      translucent paper with the appropriate width and cuts it      synchronizing with data.   The following standard values are defined for input-trays (from ISO   DPA and the Printer MIB):    'top': The top input tray in the printer.    'middle': The middle input tray in the printer.    'bottom': The bottom input tray in the printer.    'envelope': The envelope input tray in the printer.    'manual': The manual feed input tray in the printer.    'large-capacity': The large capacity input tray in the printer.    'main': The main input tray    'side': The side input trayHastings, et al.            Standards Track                   [Page 201]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The following standard values are defined for media sizes (from ISO   DPA): 'iso-a0': Specifies the ISO A0 size: 841 mm by 1189 mm as defined in    ISO 216 'iso-a1': Specifies the ISO A1 size: 594 mm by 841 mm as defined in    ISO 216 'iso-a2': Specifies the ISO A2 size: 420 mm by 594 mm as defined in    ISO 216 'iso-a3': Specifies the ISO A3 size: 297 mm by 420 mm as defined in    ISO 216 'iso-a4': Specifies the ISO A4 size: 210 mm by 297 mm as defined in    ISO 216 'iso-a5': Specifies the ISO A5 size: 148 mm by 210 mm as defined in    ISO 216 'iso-a6': Specifies the ISO A6 size: 105 mm by 148 mm as defined in    ISO 216 'iso-a7': Specifies the ISO A7 size: 74 mm by 105 mm as defined in    ISO 216 'iso-a8': Specifies the ISO A8 size: 52 mm by 74 mm as defined in ISO    216 'iso-a9': Specifies the ISO A9 size: 37 mm by 52 mm as defined in ISO    216 'iso-a10': Specifies the ISO A10 size: 26 mm by 37 mm as defined in    ISO 216 'iso-b0': Specifies the ISO B0 size: 1000 mm by 1414 mm as defined in    ISO 216 'iso-b1': Specifies the ISO B1 size: 707 mm by 1000 mm as defined in    ISO 216 'iso-b2': Specifies the ISO B2 size: 500 mm by 707 mm as defined in    ISO 216 'iso-b3': Specifies the ISO B3 size: 353 mm by 500 mm as defined in    ISO 216 'iso-b4': Specifies the ISO B4 size: 250 mm by 353 mm as defined in    ISO 216 'iso-b5': Specifies the ISO B5 size: 176 mm by 250 mm as defined in    ISO 216 'iso-b6': Specifies the ISO B6 size: 125 mm by 176 mm as defined in    ISO 216 'iso-b7': Specifies the ISO B7 size: 88 mm by 125 mm as defined in    ISO 216 'iso-b8': Specifies the ISO B8 size: 62 mm by 88 mm as defined in ISO    216 'iso-b9': Specifies the ISO B9 size: 44 mm by 62 mm as defined in ISO    216 'iso-b10': Specifies the ISO B10 size: 31 mm by 44 mm as defined in    ISO 216Hastings, et al.            Standards Track                   [Page 202]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'na-letter': Specifies the North American letter size: 8.5 inches by    11 inches 'na-legal': Specifies the North American legal size: 8.5 inches by 14    inches 'na-8x10': Specifies the North American 8 inches by 10 inches 'na-5x7': Specifies the North American 5 inches by 7 inches 'executive': Specifies the executive size (7.25 X 10.5 in) 'folio': Specifies the folio size (8.5 X 13 in) 'invoice': Specifies the invoice size (5.5 X 8.5 in) 'ledger': Specifies the ledger size (11 X 17 in) 'quarto': Specifies the quarto size (8.5 X 10.83 in) 'iso-c3': Specifies the ISO C3 size: 324 mm by 458 mm as defined in    ISO 269 'iso-c4': Specifies the ISO C4 size: 229 mm by 324 mm as defined in    ISO 269 'iso-c5': Specifies the ISO C5 size: 162 mm by 229 mm as defined in    ISO 269 'iso-c6': Specifies the ISO C6 size: 114 mm by 162 mm as defined in    ISO 269 'iso-designated-long': Specifies the ISO Designated Long size: 110 mm    by 220 mm as defined in ISO 269 'na-10x13-envelope': Specifies the North American 10x13 size: 10    inches by 13 inches 'na-9x12-envelope': Specifies the North American 9x12 size: 9 inches    by 12 inches 'na-number-10-envelope': Specifies the North American number 10    business envelope size: 4.125 inches by 9.5 inches 'na-7x9-envelope': Specifies the North American 7x9 inch envelope    size 'na-9x11-envelope': Specifies the North American 9x11 inch envelope    size 'na-10x14-envelope': Specifies the North American 10x14 inch envelope    size 'na-number-9-envelope': Specifies the North American number 9    business envelope size 'na-6x9-envelope': Specifies the North American 6x9 envelope size 'na-10x15-envelope': Specifies the North American 10x15 envelope size 'monarch-envelope': Specifies the Monarch envelope size (3.87 x 7.5    in) 'jis-b0': Specifies the JIS B0 size: 1030mm x 1456mm 'jis-b1': Specifies the JIS B1 size: 728mm x 1030mm 'jis-b2': Specifies the JIS B2 size: 515mm x 728mm 'jis-b3': Specifies the JIS B3 size: 364mm x 515mm 'jis-b4': Specifies the JIS B4 size: 257mm x 364mm 'jis-b5': Specifies the JIS B5 size: 182mm x 257mm 'jis-b6': Specifies the JIS B6 size: 128mm x 182mm 'jis-b7': Specifies the JIS B7 size: 91mm x 128mm 'jis-b8': Specifies the JIS B8 size: 64mm x 91mmHastings, et al.            Standards Track                   [Page 203]

RFC 2911              IPP/1.1: Model and Semantics        September 2000 'jis-b9': Specifies the JIS B9 size: 45mm x 64mm 'jis-b10': Specifies the JIS B10 size: 32mm x 45mm   The following standard values are defined for American Standard (i.e.   ANSI) engineering media sizes:    'a': Specifies the engineering ANSI A size medium: 8.5 inches x 11       inches    'b': Specifies the engineering ANSI B size medium: 11 inches x 17       inches    'c': Specifies the engineering ANSI C size medium: 17 inches x 22       inches    'd': Specifies the engineering ANSI D size medium: 22 inches x 34       inches    'e': Specifies the engineering ANSI E size medium: 34 inches x 44       inches   The following standard values are defined for American Architectural   engineering media sizes:    'arch-a': Specifies the Architectural A size medium: 9 inches x 12       inches    'arch-b': Specifies the Architectural B size medium: 12 inches x 18       inches    'arch-c': Specifies the Architectural C size medium: 18 inches x 24       inches    'arch-d': Specifies the Architectural D size medium: 24 inches x 36       inches    'arch-e': Specifies the Architectural E size medium: 36 inches x 48       inchesHastings, et al.            Standards Track                   [Page 204]

RFC 2911              IPP/1.1: Model and Semantics        September 200014.1. Examples   Below are examples to supplement the engineering media value   definitions.   Example 1:  "Synchro-Cut", a device cutting the roll paper in   synchronization with the data     data height:          A1 height     data width (shaded):  A1 width < data width < (A1 width) x 2     specified value:      'iso-a1xsynchro-white'               |                    |               |<--- data width --->|               |                    |               |              |     |        |               |<- A1 width ->|<- A1 width ->|               |              |     |        |     cross  ^  |              |     |        |      feed  |  +--------------------------------------------/ direction  |  |//////////////|/////|        |     ^       /            |  |//////////////|/////|        |     |      /            |  |//////////////|/////|        |     |     /            |  |//////////////|/////|        |     |     \<-----------+- |//////////////|/////|        |    A1      \  rollfeed        |  |//////////////|/////|        |   height    \  paperdirection      |//////////////|/////|        |     |        \               |//////////////|/////|        |     |        /               |//////////////|/////|        |     v       /               +------------------------------------------/                                    |                                    |                                    |<------ CUT HERE (to synchronize                                    |                with data width)                                    |Hastings, et al.            Standards Track                   [Page 205]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Example 2: "Auto-Cut", a device cutting the roll paper at multiples   of fixed-size media width     data height:          A1 height     data width (shaded):  A1 width < data width < (A1 width) x 2     specified value:      'auto-fixed-size-white'                 |                    |                 |<--- data width --->|                 |                    |                 |              |     |        |                 |<- A1 width ->|<- A1 width ->|                 |              |     |        |     cross  ^    |              |     |        |      feed  |    +--------------------------------------------/ direction  |    |//////////////|/////|        |     ^       /            |    |//////////////|/////|        |     |      /            |    |//////////////|/////|        |     |     /            |    |//////////////|/////|        |     |     \<-----------+-   |//////////////|/////|        |    A1      \  rollfeed        |    |//////////////|/////|        |   height    \  paperdirection        |//////////////|/////|        |     |        \                 |//////////////|/////|        |     |        /                 |//////////////|/////|        |     v       /                 +------------------------------------------/                                               |                                               |                                               |<--- CUT HERE                                               |      (to synchronize                                               |       with data width)Hastings, et al.            Standards Track                   [Page 206]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Example 3:  the 'iso-a4x4-white' fixed size paper     paper height:         A4 height     paper width:          (A4 width) x 4     specified value:      'iso-a4x4-white'   |              |              |              |              |   |<- A4 width ->|<- A4 width ->|<- A4 width ->|<- A4 width ->|   |              |              |              |              |   |              |              |              |              |   +-----------------------------------------------------------+   |       ^      |              |              |              |   |       |      |              |              |              |   |       |      |              |              |              |   |      A4      |              |              |              |   |    height    |              |              |              |   |       |      |              |              |              |   |       |      |              |              |              |   |       |      |              |              |              |   |       v      |              |              |              |   +-----------------------------------------------------------+Hastings, et al.            Standards Track                   [Page 207]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Example 4: "Synchro-Cut", a device cutting the fixed size paper in   synchronization with the data     data height:          A4 height     data width (shaded):  (A4 width) x 2 < data width < (A4 width) x 3     specified value:      'iso-a4xsynchro-white'                    |                                   |                    |<---------- data width ----------->|                    |                                   |                    |              |              |     |        |                    |<- A4 width ->|<- A4 width ->|<- A4 width ->|                    |              |              |     |        |        cross  ^    |              |              |     |        |         feed  |    +--------------------------------------------+    direction  |    |//////////////|//////////////|/////|    ^   |               |    |//////////////|//////////////|/////|    |   |               |    |//////////////|//////////////|/////|    |   |               |    |//////////////|//////////////|/////|    |   |   <-----------+-   |//////////////|//////////////|/////|   A4   |   feed        |    |//////////////|//////////////|/////| height |   direction        |//////////////|//////////////|/////|    |   |                    |//////////////|//////////////|/////|    |   |                    |//////////////|//////////////|/////|    v   |                    +--------------------------------------------+                                                        |                                          CUT HERE ---->|                                    (to synchronize     |                                    with data width)    |15. APPENDIX D: Processing IPP Attributes   When submitting a print job to a Printer object, the IPP model allows   a client to supply operation and Job Template attributes along with   the document data.  These Job Template attributes in the create   request affect the rendering, production and finishing of the   documents in the job.  Similar types of instructions may also be   contained in the document to be printed, that is, embedded within the   print data itself.  In addition, the Printer has a set of attributes   that describe what rendering and finishing options which are   supported by that Printer.  This model, which allows for flexibility   and power, also introduces the potential that at job submission time,   these client-supplied attributes may conflict with either:      - what the implementation is capable of realizing (i.e., what the        Printer supports), as well as      - the instructions embedded within the print data itself.Hastings, et al.            Standards Track                   [Page 208]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The following sections describe how these two types of conflicts are   handled in the IPP model.15.1 Fidelity   If there is a conflict between what the client requests and what a   Printer object supports, the client may request one of two possible   conflict handling mechanisms:      1) either reject the job since the job can not be processed         exactly as specified, or      2) allow the Printer to make any changes necessary to proceed with         processing the Job the best it can.   In the first case the client is indicating to the Printer object:   "Print the job exactly as specified with no exceptions, and if that   can't be done, don't even bother printing the job at all." In the   second case, the client is indicating to the Printer object: "It is   more important to make sure the job is printed rather than be   processed exactly as specified; just make sure the job is printed   even if some client-supplied attributes need to be changed or   ignored."   The IPP model accounts for this situation by introducing an "ipp-   attribute-fidelity" attribute.   In a create request, "ipp-attribute-fidelity" is a boolean operation   attribute that is OPTIONALLY supplied by the client.  The value   'true' indicates that total fidelity to client supplied Job Template   attributes and values is required.  The client is requesting that the   Job be printed exactly as specified, and if that is not possible then   the job MUST be rejected rather than processed incorrectly.  The   value 'false' indicates that a reasonable attempt to print the Job is   acceptable.  If a Printer does not support some of the client   supplied Job Template attributes or values, the Printer MUST ignore   them or substitute any supported value for unsupported values,   respectively.  The Printer may choose to substitute the default value   associated with that attribute, or use some other supported value   that is similar to the unsupported requested value.  For example, if   a client supplies a "media" value of 'na-letter', the Printer may   choose to substitute 'iso-a4' rather than a default value of   'envelope'. If the client does not supply the "ipp-attribute-   fidelity" attribute, the Printer assumes a value of 'false'.   Each Printer implementation MUST support both types of "fidelity"   printing (that is whether the client supplies a value of 'true' or   'false'):Hastings, et al.            Standards Track                   [Page 209]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      - If the client supplies 'false' or does not supply the attribute,        the Printer object MUST always accept the request by ignoring        unsupported Job Template attributes and by substituting        unsupported values of supported Job Template attributes with        supported values.      - If the client supplies 'true', the Printer object MUST reject        the request if the client supplies unsupported Job Template        attributes.   Since a client can always query a Printer to find out exactly what is   and is not supported, "ipp-attribute-fidelity" set to 'false' is   useful when:      1) The End-User uses a command line interface to request         attributes that might not be supported.      2) In a GUI context, if the End User expects the job might be         moved to another printer and prefers a sub-optimal result to         nothing at all.      3) The End User just wants something reasonable in lieu of nothing         at all.15.2 Page Description Language (PDL) Override   If there is a conflict between the value of an IPP Job Template   attribute and a corresponding instruction in the document data, the   value of the IPP attribute SHOULD take precedence over the document   instruction.  Consider the case where a previously formatted file of   document data is sent to an IPP Printer.  In this case, if the client   supplies any attributes at job submission time, the client desires   that those attributes override the embedded instructions.  Consider   the case were a previously formatted document has embedded in it   commands to load 'iso-a4' media.  However, the document is passed to   an end user that only has access to a printer with 'na-letter' media   loaded.  That end user most likely wants to submit that document to   an IPP Printer with the "media" Job Template attribute set to 'na-   letter'.  The job submission attribute should take precedence over   the embedded PDL instruction.  However, until companies that supply   document data interpreters allow a way for external IPP attributes to   take precedence over embedded job production instructions, a Printer   might not be able to support the semantics that IPP attributes   override the embedded instructions.   The IPP model accounts for this situation by introducing a "pdl-   override-supported" attribute that describes the Printer objects   capabilities to override instructions embedded in the PDL data   stream.  The value of the "pdl-override-supported" attribute is   configured by means outside the scope of this IPP/1.1 document.Hastings, et al.            Standards Track                   [Page 210]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   This REQUIRED Printer attribute takes on the following values:      - 'attempted': This value indicates that the Printer object        attempts to make the IPP attribute values take precedence over        embedded instructions in the document data, however there is no        guarantee.      - 'not-attempted': This value indicates that the Printer object        makes no attempt to make the IPP attribute values take        precedence over embedded instructions in the document data.   At job processing time, an implementation that supports the value of   'attempted' might do one of several different actions:      1) Generate an output device specific command sequence to realize         the feature represented by the IPP attribute value.      2) Parse the document data itself and replace the conflicting         embedded instruction with a new embedded instruction that         matches the intent of the IPP attribute value.      3) Indicate to the Printer that external supplied attributes take         precedence over embedded instructions and then pass the         external IPP attribute values to the document data interpreter.      4) Anything else that allows for the semantics that IPP attributes         override embedded document data instructions.   Since 'attempted' does not offer any type of guarantee, even though a   given Printer object might not do a very "good" job of attempting to   ensure that IPP attributes take a higher precedence over instructions   embedded in the document data, it would still be a conforming   implementation.   At job processing time, an implementation that supports the value of   'not-attempted' might do one of the following actions:      1) Simply pre-pend the document data with the PDL instruction that         corresponds to the client-supplied PDL attribute, such that if         the document data also has the same PDL instruction, it will         override what the Printer object pre-pended.  In other words,         this implementation is using the same implementation semantics         for the client-supplied IPP attributes as for the Printer         object defaults.      2) Parse the document data and replace the conflicting embedded         instruction with a new embedded instruction that approximates,         but does not match, the semantic intent of the IPP attribute         value.   Note:  The "ipp-attribute-fidelity" attribute applies to the   Printer's ability to either accept or reject other unsupported JobHastings, et al.            Standards Track                   [Page 211]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   Template attributes.  In other words, if "ipp-attribute-fidelity" is   set to 'true', a Job is accepted if and only if the client supplied   Job Template attributes and values are supported by the Printer.   Whether these attributes actually affect the processing of the Job   when the document data contains embedded instructions depends on the   ability of the Printer to override the instructions embedded in the   document data with the semantics of the IPP attributes.  If the   document data attributes can be overridden ("pdl-override-supported"   set to 'attempted'), the Printer makes an attempt to use the IPP   attributes when processing the Job. If the document data attributes   can not be overridden ("pdl-override-supported" set to 'not-   attempted'), the Printer makes no attempt to override the embedded   document data instructions with the IPP attributes when processing   the Job, and hence, the IPP attributes may fail to affect the Job   processing and output when the corresponding instruction is embedded   in the document data.15.3 Using Job Template Attributes During Document Processing.   The Printer object uses some of the Job object's Job Template   attributes during the processing of the document data associated with   that job.  These include, but are not limited to, "orientation-   requested", "number-up", "sides", "media", and "copies".  The   processing of each document in a Job Object MUST follow the steps   below. These steps are intended only to identify when and how   attributes are to be used in processing document data and any   alternative steps that accomplishes the same effect can be used to   implement this specification document.      1. Using the client supplied "document-format" attribute or some         form of document format detection algorithm (if the value of         "document-format" is not specific enough), determine whether or         not the document data has already been formatted for printing.         If the document data has been formatted, then go to step 2.         Otherwise, the document data MUST be formatted. The formatting         detection algorithm is implementation defined and is not         specified by this document.  The formatting of the document         data uses the "orientation-requested" attribute to determine         how the formatted print data should be placed on a print-stream         page, seesection 4.2.10 for the details.      2. The document data is in the form of a print-stream in a known         media type. The "page-ranges" attribute is used to select, as         specified insection 4.2.7, a sub-sequence of the pages in the         print-stream that are to be processed and images.      3. The input to this step is a sequence of print-stream pages.         This step is controlled by the "number-up" attribute. If theHastings, et al.            Standards Track                   [Page 212]

RFC 2911              IPP/1.1: Model and Semantics        September 2000         value of "number-up" is N, then during the processing of the         print-stream pages, each N print-stream pages are positioned,         as specified insection 4.2.9, to create a single impression.         If a given document does not have N more print-stream pages,         then the completion of the impression is controlled by the         "multiple-document-handling" attribute as described insection4.2.4; when the value of this attribute is 'single-document' or         'single-document-new-sheet', the print-stream pages of document         data from subsequent documents is used to complete the         impression.         The size(scaling), position(translation) and rotation of the         print-stream pages on the impression is implementation defined.         Note that during this process the print-stream pages may be         rendered to a form suitable for placing on the impression; this         rendering is controlled by the values of the "printer-         resolution" and "print-quality" attributes as described in         sections4.2.12 and4.2.13. In the case N=1, the impression is         nearly the same as the print-stream page; the differences would         only be in the size, position and rotation of the print-stream         page and/or any decoration, such as a frame to the page, that         is added by the implementation.      4. The collection of impressions is placed, in sequence, onto         sides of the media sheets. This placement is controlled by the         "sides" attribute and the orientation of the print-stream page,         as described insection 4.2.8. The orientation of the print-         stream pages affects the orientation of the impression; for         example, if "number-up" equals 2, then, typically, two portrait         print-stream pages become one landscape impression. Note that         the placement of impressions onto media sheets is also         controlled by the "multiple-document-handling" attribute as         described insection 4.2.4.      5. The "copies" and "multiple-document-handling" attributes are         used to determine how many copies of each media instance are         created and in what order. See sections4.2.5 and4.2.4 for the         details.      6. When the correct number of copies are created, the media         instances are finished according to the values of the         "finishings" attribute as described in 4.2.6. Note that         sometimes finishing operations may require manual intervention         to perform the finishing operations on the copies, especially         uncollated copies. This document allows any or all of the         processing steps to be performed automatically or manually at         the discretion of the Printer object.Hastings, et al.            Standards Track                   [Page 213]

RFC 2911              IPP/1.1: Model and Semantics        September 200016. APPENDIX E: Generic Directory Schema   This section defines a generic schema for an entry in a directory   service.  A directory service is a means by which service users can   locate service providers.  In IPP environments, this means that IPP   Printers can be registered (either automatically or with the help of   an administrator) as entries of type printer in the directory using   an implementation specific mechanism such as entry attributes, entry   type fields, specific branches, etc.  Directory clients can search or   browse for entries of type printer.  Clients use the directory   service to find entries based on naming, organizational contexts, or   filtered searches on attribute values of entries.  For example, a   client can find all printers in the "Local Department" context.   Authentication and authorization are also often part of a directory   service so that an administrator can place limits on end users so   that they are only allowed to find entries to which they have certain   access rights.  IPP itself does not require any specific directory   service protocol or provider.   Note: Some directory implementations allow for the notion of   "aliasing".  That is, one directory entry object can appear as   multiple directory entry object with different names for each object.   In each case, each alias refers to the same directory entry object   which refers to a single IPP Printer object.   The generic schema is a subset of IPP Printer Job Template and   Printer Description attributes (sections4.2 and4.4).  These   attributes are identified as either RECOMMENDED or OPTIONAL for the   directory entry itself.  This conformance labeling is NOT the same   conformance labeling applied to the attributes of IPP Printers   objects.  The conformance labeling in this Appendix is intended to   apply to directory templates and to IPP Printer implementations that   subscribe by adding one or more entries to a directory.  RECOMMENDED   attributes SHOULD be associated with each directory entry.  OPTIONAL   attributes MAY be associated with the directory entry (if known or   supported).  In addition, all directory entry attributes SHOULD   reflect the current attribute values for the corresponding Printer   object.   The names of attributes in directory schema and entries SHOULD be the   same as the IPP Printer attribute names as shown, as much as   possible.   In order to bridge between the directory service and the IPP Printer   object, one of the RECOMMENDED directory entry attributes is the   Printer object's "printer-uri-supported" attribute.  The directory   client queries the "printer-uri-supported" attribute (or its   equivalent) in the directory entry and then the IPP client addressesHastings, et al.            Standards Track                   [Page 214]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   the IPP Printer object using one of its URIs.  The "uri-security-   supported" attribute identifies the protocol (if any) used to secure   a channel.   The following attributes define the generic schema for directory   entries of type PRINTER:     printer-uri-supported              RECOMMENDEDSection 4.4.1     uri-authentication-supported       RECOMMENDEDSection 4.4.2     uri-security-supported             RECOMMENDEDSection 4.4.3     printer-name                       RECOMMENDEDSection 4.4.4     printer-location                   RECOMMENDEDSection 4.4.5     printer-info                       OPTIONALSection 4.4.6     printer-more-info                  OPTIONALSection 4.4.7     printer-make-and-model             RECOMMENDEDSection 4.4.9     ipp-versions-supported             RECOMMENDEDSection 4.4.14     multiple-document-jobs-supported   OPTIONALSection 4.4.16     charset-supported                  OPTIONALSection 4.4.18     generated-natural-language-        supported                       OPTIONALSection 4.4.20     document-format-supported          RECOMMENDEDSection 4.4.22     color-supported                    RECOMMENDEDSection 4.4.26     compression-supported              RECOMMENDEDSection 4.4.32     pages-per-minute                   OPTIONALSection 4.4.36     pages-per-minute-color             OPTIONALSection 4.4.37     finishings-supported               OPTIONALSection 4.2.6     number-up-supported                OPTIONALSection 4.2.7     sides-supported                    RECOMMENDEDSection 4.2.8     media-supported                    RECOMMENDEDSection 4.2.11     printer-resolution-supported       OPTIONALSection 4.2.12     print-quality-supported            OPTIONALSection 4.2.1317. APPENDIX F:Differences between the IPP/1.0 and IPP/1.1 "Model and    Semantics" Documents   This Appendix is divided into two lists that summarize the   differences between IPP/1.1 (this document) and IPP/1.0 [RFC2566].   The section numbers refer to the numbers in this document which in   some cases have changed fromRFC 2566.  When a change affects   multiple sections, the item is listed once in the order of the first   section affected and the remaining affected section numbers are   indicated.Hastings, et al.            Standards Track                   [Page 215]

RFC 2911              IPP/1.1: Model and Semantics        September 2000   The first list contains extensions and clarifications and the second   list contains changes in semantics or conformance.  However, client   and IPP object implementations of IPP/1.0 MAY implement any of the   extensions and clarifications in this document.   The following extensions and clarifications have been incorporated   into this document:      1.Section 2.1 - clarified that the term "client" can be either          contained in software controlled by an end user or a part of a          print server that controls devices.      2.Section 2 - clarified that the term "IPP object" and "Printer          object" can either be embedded in a device object or part of a          print server that accepts IPP requests.      3.Section 2.4 - added the description of the new "uri-          authentication-supported" Printer Description attribute.      4.Section 3.1.3, 3.1.6, 3.2.5.2, and 3.2.6.2 - clarified the          error handling for operation attributes that have their own          status code.      5.Section 3.1.3 - clarified that multiple occurrences of the          same attribute in an attribute group is mal-formed.  An IPP          Printer MAY reject the request or choose one of the          attributes.      6.Section 3.1.6 - reorganized this section into sub-sections to          separately describe "status-code", "status-message",          "detailed-status-message", and "document-access-error"          attributes.      7.Section 3.1.6.1 - clarified the error status codes and their          relationship to operation attributes.      8.Section 3.1.6.3 - Added the OPTIONAL "detailed-status-message          (text(MAX))" operation attribute to provide additional more          detailed information about a response.      9.Section 3.1.6.4 and 3.2.2 - Added the OPTIONAL "document-          access-error (text(MAX))" operation attribute for use with          Print-URI and Send-URI responses.      10. Sections3.1.7 - Added this new section to clarify returning          Unsupported Attributes for all operations, including only          returning attributes that were in the request.  Moved the text          fromsection 3.2.1.2 Unsupported Attributes to this section.      11. Sections3.1.7 and4.1 - clarified the encoding of the "out-          of-band" 'unsupported' and 'unknown' values.      12.Section 3.1.8 - clarified that only the version number          parameter will be carried forward into future major or minor          versions of the protocol.      13.Section 3.1.8 - relaxed the requirements to increment the          major version number in future versions of the Model and          Semantics document.Hastings, et al.            Standards Track                   [Page 216]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      14.Section 3.1.9, and 3.2.5 - added the 'processing' state to the          list of job states that a job can be in after a Create-Job          operation.      15.Section 3.1.9 - clarified that a non-spooling Printer MAY          accept zero or more subsequent jobs while processing a job and          flow control them down.  Subsequent create requests are          rejected with the 'server-error-busy' error status.      16.Section 3.2.1.1 - clarified the validation of the          "compression" operation attribute and its relationship to the          validation of the "document-format" attribute and returning          Unsupported Attributes.      17. Sections3.2.1.1,4.3.8,13.1.4.16, and13.1.4.17 - added the          'client-error-compression-not-supported', 'client-error-          compression-error' status codes and the 'unsupported-          compression' and 'compression-error' job-state-reasons.      18. Sections3.2.1.1 and4.3.8 - added 'unsupported-document-          format' and 'document-format-error' job-state-reasons.      19. Sections3.2.2,4.3.8 and13.1.4.19 - added 'client-error-          document-access-error' status code and 'document-access-error'          job state reason.      20.Section 3.2.5.2 and 3.2.6.2 - clarified that the Unsupported          Attributes group MUST NOT include attributes not requested in          the Get-Printer-Attributes request.      21.Section 3.2.6 - clarified that "limit" takes precedence over          "which-jobs" and "my-jobs'.      22.Section 3.2.6.2 - clarified that Get-Jobs returns          'successful-ok' when no jobs to return.      23. Sections3.2.7,3.2.8, and3.2.9 - added the OPTIONAL Pause-          Printer, Resume-Printer, and Purge-Jobs operations      24.Section 3.3.1  - clarified that the authorization required for          a Send-Document request MUST be the same user as the Create-          Job or an operator.      25.Section 3.3.1.1 - clarified that a Create-Job Send-Document          with "last-document" = 'true' and no data is not an error; its          a job with no documents.      26. Sections3.3.5,3.3.6, and3.3.7 - added the OPTIONAL Hold-          Job, Release-Job, and Restart-Job operations.  Clarified the          Restart-Job operation so that the Printer MUST re-fetch any          documents passed by-reference (Print-URI or Send-URI).      27.Section 4.1 - clarified that the encoding of the out-of-band          values are specified in the Encoding and Transport" document.      28.Section 4.1 - Clarified that the requirement that clients MUST          NOT send "out-of-band" values in requests applies only to          operations defined in this document.  Other operations are          allowed to define "out-of-band" values that clients can          supply.Hastings, et al.            Standards Track                   [Page 217]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      29. Sections4.1.1 and4.1.2 - clarified that the maximum 'text'          and 'name' values of 1023 and 255 are for the          'textWithoutLanguage' portion of the 'textWithLanguage' form,          so that the maximum number of octets for the actual text and          name data is the same for the without and with language forms;          the 'naturalLanguage' part is in addition.      30.Section 4.1.9 - clarified that 'mimeMediaType' values can          include any parameters from the IANA Registry, not just          charset parameters.      31.Section 4.1.9.1 - clarified that 'application/octet-stream'          auto-sensing can happen at create request time and/or          job/document processing time.      32.Section 4.1.9.1 - clarified that auto-sensing involves the          Printer examining some number of octets of document data using          an implementation-dependent method.      33.Section 4.1.14 - clarified that the localization of dateTime          by the client includes the time zone.      34.Section 4.2 - clarified that xxx-supported have multiple          keywords and/or names by adding parentheses to the table to          give:  (1setOf (type3 keyword | name))      35.Section 4.2.2 - added the 'indefinite' keyword value to the          "job-hold-until" attribute for use with the create operations          and Hold-Job and Restart-Job operations.      36.Section 4.2.6 - added more enum values to the "finishings" Job          Template attribute.      37.Section 4.2.6 - clarified that the landscape definition is a          rotation of the image with respect to the medium.      38.Section 4.3.7 - added that a forwarding server that cannot get          any job state MAY return the job's state as 'completed',          provided that it also return the new 'queued-in-device' job          state reason.      39.Section 4.3.7.2 - added the Partitioning of Job States section          to clarify the concepts of Job Retention, Job History, and Job          Removal.      40.Section 4.3.8 - added 'job-data-insufficient' job state reason          to indicate whether sufficient data has arrived for the          document to start to be processed.      41.Section 4.3.8 - added 'document-access-error' job state reason          to indicate an access error of any kind.      42.Section 4.3.8 - added 'job-queued-for-marker' job state reason          to indicate whether the job has completed some processing and          is waiting for the marker.      43.Section 4.3.8 - added 'unsupported-compression' and          'compression-error' job state reasons to indicate compression          not supported or compression processing error after the create          has been accepted.Hastings, et al.            Standards Track                   [Page 218]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      44.Section 4.3.8 - added 'unsupported-document-format' and          'document-format-error' job state reasons to indicate document          not supported or document format processing error after the          create has been accepted.      45.Section 4.3.8 - added 'queued-in-device' job state reason to          indicate that a job as been forwarded to a print system or          device that does not provide any job status.      46.Section 4.3.10 - added "job-detailed-status-messages (1setOf          text(MAX)) for returning detailed error messages.      47.Section 4.3.11 - added the "job-document-access-errors (1setOf          text(MAX))      48.Section 4.3.14.2 - clarified that the time recorded is the          first time processing since the create operation or the          Restart-Job operation.      49.Section 4.3.14.2 and 4.3.14.3 - clarified that the out-of-band          value 'no-value' is returned if the job has not started          processing or has not completed, respectively.      50.Section 4.3.14 - Added the OPTIONAL "date-time-at-creation",          "date-time-at-processing", and "date-time-at-completed" Event          Time Job Description attributes      51.Section 4.4.3 - added the 'tls' value to "uri-security-          supported" attribute.      52.Section 4.4.3 - clarified "uri-security-supported" is          orthogonal to Client Authentication so that 'none' does not          exclude Client Authentication.      53.Section 4.4.11 - simplified the "printer-state" descriptions          while generalizing to allow high end devices that interpret          one or more jobs while marking another.  Indicated that          'spool-area-full' and 'stopped-partly' "printer-state-reasons"          may be used to provide further state information.      54.Section 4.4.12 - added the 'moving-to-paused' keyword value to          the "printer-state-reasons" attribute for use with the Pause-          Printer operation.      55.Section 4.4.12 - replaced the duplicate 'marker-supply-low'          keyword with the missing 'toner-empty' keyword for the          "printer-state-reasons" attribute.  (This correction was also          made beforeRFC 2566 was published).      56.Section 4.4.12 - clarified 'spool-area-full' "printer-state-          reasons" to include non-spooling printers to indicate when it          can and cannot accept another job.      57.Section 4.4.15 - added the enum values to the "operations-          supported" attribute for the new operations.  Clarified that          the values of this attribute are encoded as any enum, namely          32-bit values.      58.Section 4.4.30 - clarified that the dateTime value of          "printer-current-time" is on a "best efforts basis".  If a          proper date-time cannot be obtained, the implementation          returns the 'no-value' out-of-band value.  Also clarified thatHastings, et al.            Standards Track                   [Page 219]

RFC 2911              IPP/1.1: Model and Semantics        September 2000          the time zone NEED NOT be the time zone that the people near          the device use and that the client SHOULD display the dateTime          attributes in the user's local time.      59. Sections4.4.36 and4.4.37 - added the OPTIONAL "pages-per-          minute" and "pages-per-minute-color" Printer Description          attributes.      60.Section 5.1 - clarified that the client conformance          requirements apply to clients controlled by an end user and          clients in servers.      61.Section 5.1 - clarified that any response MAY contain          additional attribute groups, attributes, attribute syntaxes,          or attribute values.      62.Section 5.1 - clarified that a client SHOULD do its best to          prevent a channel from being closed by a lower layer when the          channel is flow controlled off by the IPP Printer.      63.Section 5.2 - clarified that the IPP object requirements apply          to objects embedded in devices or that are parts of servers.      64.Section 5.2.2 - clarified that IPP objects MAY return          operation responses that contain attribute groups, attribute          names, attribute syntaxes, attribute values, and status codes          that are extensions to this standard.      65.Section 6 - changed the terminology of "private extensions" to          "vendor extensions" and indicated that they are registered          with IANA along with IETF standards track extensions.      66.Section 6.7 - inserted this section on registering out-of-band          attribute values with IANA as extensions.      67.Section 8.3 - clarified the use of URIs for each Client          Authentication mechanism.      68.Section 8.5 - added the security discussion around the new          operator/administrator operations.      69.Section 13.1.4.16 - added client-error-compression-not-          supported (0x040F)      70.Section 13.1.4.17 - added client-error-compression-error          (0x0410)      71.Section 13.1.4.18 - added client-error-document-format-error          (0x0411)      72.Section 13.1.4.19 - added client-error-document-access-error          (0x0412)      73.Section 13.1.5.10 - added server-error-multiple-document-          jobs-not-supported (0x0509)      74.Section 14 - added 'a-white', 'b-white', 'c-white', 'd-white',          and 'e-white' and clarified that the existing 'a', 'b', 'c',          'd', and 'e' values are size values.  Added American,          Japanese, and European Engineering sizes, filled out          -transparent and - translucent media names and drawings for          the synchro cut sizes.Hastings, et al.            Standards Track                   [Page 220]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      75.Section 16 - softened the RECOMMENDATION for IPP Printer          attributes in a Directory schema so that they can have          equivalents.      76.Section 16 - added the OPTIONAL "pages-per-minute" and          "pages-per-minute-color" Printer attributes to the Directory          schema.      77.Section 16 - added OPTIONAL "multiple-document-jobs-supported"          to the Directory schema.      78.Section 16 - added RECOMMENDED "uri-authentication-supported",          "ipp-versions-supported", and "compression-supported" to the          Directory schema.   The following changes in semantics and/or conformance have been   incorporated into this document:      1.Section 3.1.6.3 - allowed a Printer to localize the          "detailed-status-message" operation response attribute, but          indicated that such localization might obscure the technical          meaning of such messages.      2.Section 3.1.8, 5.2.4, and 13.1.5.4 - Clients and IPP objects          MUST support version 1.1 conformance requirements.   It is          recommended that they interoperate with 1.0.  Also clarified          that IPP Printers MUST accept '1.1' requests.   It is          recommended that they also accept '1.x' requests.      3.Section 3.2.1.1 andsection 4.4.32 - changed the "compression"          operation and the "compression-supported" Printer Description          attribute from OPTIONAL to REQUIRED.      4.  Sections3.2.1.2 and4.3.8 - changed "job-state-reasons" from          RECOMMENDED to REQUIRED, so that "job-state-reasons" MUST be          returned in create operation responses.      5.  Sections3.2.4,3.3.1,4.4.16, and16 - changed Create-          Job/Send-Document so that they MAY be implemented while only          supporting one document jobs.  Added the "multiple-document-          jobs-supported" boolean Printer Description attribute to          indicate whether Create-Job/Send-Document support multiple          document jobs or not.  Added to the Directory schema.      6.Section 4.1.9 - deleted 'text/plain; charset=iso-10646-ucs-2',          since binary is not legal with the 'text' type.      7.Section 4.1.9.1 - added the RECOMMENDATION that a Printer          indicate by printing on the job's job-start-sheet that auto-          sensing has occurred and what document format was auto-sensed.      8.Section 4.2.4 - indicated that the "multiple-document-          handling" Job Template attribute MUST be supported with at          least one value if the Printer supports multiple documents per          jobHastings, et al.            Standards Track                   [Page 221]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      9.Section 4.3.7.2 - indicated that the 'job-restartable' job          state reason SHOULD be supported if the Restart-Job operation          is supported.      10.Section 4.3.8 - changed "job-state-reasons" from RECOMMENDED          to REQUIRED.      11.Section 4.3.8 - clarified the conformance of the values of the          "job-state-reasons" attribute by copying conformance          requirements from other sections of the document so that it is          clear from reading the definition of "job-state-reasons" which          values MUST or SHOULD be supported.  The 'none',          'unsupported-compression', and 'unsupported-document-format'          values MUST be supported.  The 'job-hold-until-specified'          SHOULD be specified if the "job-hold-until" Job Template is          supported.  The following values SHOULD be supported:  'job-          canceled-by-user', 'aborted-by-system', and 'job-completed-          successfully'.  The          'job-canceled-by-operator' SHOULD be supported if the          implementation permits canceling by other than the job owner.          The 'job-canceled-at-device' SHOULD be supported if the device          supports canceling jobs at the console.  The 'job-completed-          with-warnings' SHOULD be supported, if the implementation          detects warnings.  The 'job-completed-with-errors' SHOULD be          supported if the implementation detects errors.  The 'job-          restartable' SHOULD be supported if the Restart-Job operation          is supported.      12.Section 4.3.10 - allowed a Printer to localize the "job-          detailed-status-message" Job Description attribute, but          indicated that such localization might obscure the technical          meaning of such messages.      13.Section 4.3.14 - changed the "time-at-creation", "time-at-          processing", and "time-at-completed" Event Time Job          Description attributes from OPTIONAL to REQUIRED.      14.Section 4.3.14.4 - added the REQUIRED "job-printer-up-time          (integer(1:MAX))" Job Description attribute as an alias for          "printer-up-time" to reduce number of operations to get job          times.      15.Section 4.4.2 - added the REQUIRED "uri-authentication-          supported (1setOf type2 keyword)" Printer Description          attribute to describe the Client Authentication used by each          Printer URI.      16.Section 4.4.12 - changed "printer-state-reasons" Printer          Description attribute from OPTIONAL to REQUIRED.      17.Section 4.4.12 - changed 'paused' value of "printer-state-          reasons" to MUST if Pause-Printer operation is supported.Hastings, et al.            Standards Track                   [Page 222]

RFC 2911              IPP/1.1: Model and Semantics        September 2000      18.Section 4.4.14 - added the REQUIRED "ipp-versions-supported          (1setOf keyword)" Printer Description attribute, since IPP/1.1          Printers do not have to support version '1.0' conformance          requirements.Section 4.4.16 - added the "multiple-document-          jobs-supported (boolean)" Printer Description attribute so          that a client can tell whether a Printer that supports          Create-Job/Send-Document supports multiple document jobs or          not.  This attribute is REQUIRED if the Create-Job operation          is supported.      19.Section 4.4.24 - changed the "queued-job-count" Printer          Description attribute from RECOMMENDED to REQUIRED.      20.Section 4.4.32 - changed "compression-supported (1setOf type3          keyword)" Printer Description attribute from OPTIONAL to          REQUIRED.      21.Section 5.1 - changed the client security requirements from          RECOMMENDED non-standards track SSL3 to MUST support Client          Authentication as defined in the IPP/1.1 Encoding and          Transport document [RFC2910].  A client SHOULD support          Operation Privacy and Server Authentication as defined in the          IPP/1.1 Encoding and Transport document [RFC2910].      22.Section 5.2.7 - changed the IPP object security requirements          from OPTIONAL non-standards track SSL3 to SHOULD contain          support for Client Authentication as defined in the IPP/1.1          Encoding and Transport document [RFC2910].  A Printer          implementation MAY allow an administrator to configure the          Printer so that all, some, or none of the users are          authenticated.  An IPP Printer implementation SHOULD contain          support for Operation Privacy and Server Authentication as          defined in the IPP/1.1 Encoding and Transport document          [RFC2910].  A Printer implementation MAY allow an          administrator to configure the degree of support for Operation          Privacy and Server Authentication.  Security MUST NOT be          compromised when the client supplies a lower version-number in          a request.      23.Section 14 (Appendix C): Corrected typo, changing the keyword          'iso-10-white' to 'iso-a10-white'.   See also the "IPP/1.1 Encoding and Transport" [RFC2910] document for   differences between IPP/1.0 [RFC2565] and IPP/1.1 [RFC2910].Hastings, et al.            Standards Track                   [Page 223]

RFC 2911              IPP/1.1: Model and Semantics        September 200018.  Full Copyright Statement   Copyright (C) The Internet Society (2000).  All Rights Reserved.   This document and translations of it may be copied and furnished to   others, and derivative works that comment on or otherwise explain it   or assist in its implementation may be prepared, copied, published   and distributed, in whole or in part, without restriction of any   kind, provided that the above copyright notice and this paragraph are   included on all such copies and derivative works.  However, this   document itself may not be modified in any way, such as by removing   the copyright notice or references to the Internet Society or other   Internet organizations, except as needed for the purpose of   developing Internet standards in which case the procedures for   copyrights defined in the Internet Standards process must be   followed, or as required to translate it into languages other than   English.   The limited permissions granted above are perpetual and will not be   revoked by the Internet Society or its successors or assigns.   This document and the information contained herein is provided on an   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Acknowledgement   Funding for the RFC Editor function is currently provided by the   Internet Society.Hastings, et al.            Standards Track                   [Page 224]

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