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Network Working Group                                        L. McIntyreRequest for Comments: 3950                                    ConsultantObsoletes:3250                                               G. ParsonsCategory: Standards Track                                Nortel Networks                                                             J. Rafferty                                                   Brooktrout Technology                                                           February 2005Tag Image File Format Fax eXtended (TIFF-FX) - image/tiff-fxMIME Sub-type RegistrationStatus 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 (2005).Abstract   This document describes the registration of the MIME sub-type   image/tiff-fx.  The encodings are defined by File Format for Internet   Fax and its extensions.1.  Introduction   This document describes the registration of the MIME sub-type   image/tiff-fx.  The encodings are defined by File Format for Internet   Fax [TIFF-FX] and its extensions.   This document is a product of the IETF Internet Fax Working Group.   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this   document are to be interpreted as described inBCP 14,RFC 2119   [REQ].2.  TIFF-FX Definition   Tag Image File Format Fax eXtended (TIFF-FX), is defined in detail byRFC 3949, "File Format for Internet Fax" [TIFF-FX].McIntyre, et al.            Standards Track                     [Page 1]

RFC 3950                     image/tiff-fx                 February 2005   While a brief scope and feature description is provided in this   section as background information, the reader is directed to the   original TIFF-FX specification (File Format for Internet Fax) to   obtain complete feature and technical details.2.1.  TIFF-FX Scope   This document defines a TIFF-based file format specification for   enabling standardized messaging-based fax over the Internet.  It   specifies the TIFF fields and field values required for compatibility   with the existing ITU-T Recommendations for Group 3 black-and-white,   grayscale and color facsimile.  TIFF has historically been used for   handling fax image files in applications such as store-and-forward   messaging.  Implementations that support this file format   specification for import/export may elect to support it as a native   format.  This document recommends a TIFF file structure that is   compatible with low-memory and page-level streaming implementations.   Unless otherwise noted, the current TIFF specification [TIFF] and   selected TIFF Technical Notes [TTN1,TTN2] are the primary references   for describing TIFF and defining TIFF fields.  This document is the   primary reference for defining TIFF field values for fax   applications.2.2.  TIFF-FX Features   Some of the features of TIFF-FX are:   -  TIFF-FX is capable of describing bilevel, grayscale, palette-      color, full-color and mixed content image data.   -  TIFF-FX includes a number of compression schemes that allow      developers to choose the best space or time tradeoff for their      applications.   -  TIFF-FX is designed to be extensible and to evolve gracefully as      new needs arise.3.  MIME Definition   This document defines the image/tiff-fx MIME sub-type to refer to   TIFF-FX Profiles J, C, L and M encoded image data and any future   TIFF-FX extensions, or a subset.  The image/tiff-fx content type MAY   be used when black-and-white image data is encoded using TIFF-FX   Profiles S or F, or a subset, however, the image/tiff content type   SHOULD be used.McIntyre, et al.            Standards Track                     [Page 2]

RFC 3950                     image/tiff-fx                 February 20054.  IANA Registration   To: ietf-types@iana.org   Subject: Registration of Standard MIME media type image/tiff-fx   MIME media type name: image   MIME subtype name: tiff-fx   Required parameters: none   Optional parameters: none   Encoding Considerations:      This media type consists of binary data.  The base64 encoding      should be used on transports that cannot accommodate binary data      directly.   Security considerations:      TIFF-FX utilizes a structure which can store image data and      attributes of this image data.  The fields defined in the TIFF-FX      specification are of a descriptive nature and provide information      that is useful to facilitate viewing and rendering of images by a      recipient.  As such, the fields currently defined in the TIFF-FX      specification do not in themselves create additional security      risks, since the fields are not used to induce any particular      behavior by the recipient application.      TIFF-FX has an extensible structure, so that it is theoretically      possible that fields could be defined in the future which could be      used to induce particular actions on the part of the recipient,      thus presenting additional security risks, but this type of      capability is not supported in the referenced TIFF-FX      specification.  Indeed, the definition of fields which would      include such processing instructions is inconsistent with the      goals and spirit of the TIFF-FX specification.      The MIME type and file extension defined by this document MUST NOT      be used to blindly select a processing program.  It is up to the      implementation to determine the application (if necessary) and      render the image to the user.McIntyre, et al.            Standards Track                     [Page 3]

RFC 3950                     image/tiff-fx                 February 2005   Interoperability considerations:      The ability of implementations to handle all the defined      applications (or profiles within applications) of TIFF-FX may not      be ubiquitous.  As a result, implementations may decode and      attempt to display the encoded TIFF-FX image data only to      determine that the image cannot be rendered.   Published specification:      TIFF-FX (Tag Image File Format Fax eXtended) is defined in:RFC 3949, "File Format for Internet Fax", February 2005, Buckley,      R., Venable, D., McIntyre, L., Parsons, G., and J. Rafferty.   Applications which use this media type:      Imaging, fax, messaging and multi-media   Additional information:      Magic number(s):           II (little-endian):  49 49 2A 00 hex           MM (big-endian):     4D 4D 00 2A hex      File extension(s): .TFX      Macintosh File Type Code(s): TFX   Person & email address to contact for further information:      Lloyd McIntyre      Lloyd_McIntyre@Dell.com      Glenn W. Parsons      gparsons@nortelnetworks.com      James Rafferty      jraff@brooktrout.com   Intended usage: COMMON   Change controller: Lloyd McIntyreMcIntyre, et al.            Standards Track                     [Page 4]

RFC 3950                     image/tiff-fx                 February 20055.  Security Considerations   TIFF-FX utilizes a structure which can store image data and   attributes of this image data.  The fields defined in the TIFF-FX   specification are of a descriptive nature and provide information   that is useful to facilitate viewing and rendering of images by a   recipient.  As such, the fields currently defined in the TIFF-FX   specification do not in themselves create additional security risks,   since the fields are not used to induce any particular behavior by   the recipient application.   TIFF-FX has an extensible structure, so that it is theoretically   possible that fields could be defined in the future which could be   used to induce particular actions on the part of the recipient, thus   presenting additional security risks, but this type of capability is   not supported in the referenced TIFF-FX specification.  Indeed, the   definition of fields which would include such processing instructions   is inconsistent with the goals and spirit of the TIFF-FX   specification.   The MIME type and file extension defined by this document MUST NOT be   used to blindly select a processing program.  It is up to the   implementation to determine the application (if necessary) and render   the image to the user.6.  References6.1.  Normative References   [TIFF-FX] Buckley, R., Venable, D., McIntyre, L., Parsons, G., and J.             Rafferty, "File Format for Internet Fax",RFC 3949,             February 2005.6.2.  Informative References   [TIFF]    Adobe Developers Association, TIFF (TM) Revision 6.0 -             Final, June 3, 1992.   [REQ]     Bradner, S., "Key words for use in RFCs to Indicate             Requirement Levels",BCP 14,RFC 2119, March 1997.   [TTN1]    Adobe PageMaker 6.0 TIFF Technical Notes, Sept. 14, 1995,http://partners.adobe.com/asn/developer/pdfs/tn/TIFFPM6.pdf   [TTN2]    Adobe Photoshop TIFF Technical Notes, Replacement TIFF/JPEG             specification, March 22, 2002,http://partners.adobe.com/asn/developer/pdfs/tn/TIFFphotoshop.pdfMcIntyre, et al.            Standards Track                     [Page 5]

RFC 3950                     image/tiff-fx                 February 2005Annex A. List of edits toRFC 3250   +----+---------+-------------------------------------------------+   | No.| Section |                  Edit                           |   +----+---------+-------------------------------------------------+   | 1. | All     | Updated references fromRFC 2301 to             |   |    |         |draft-ietf-fax-tiff-fx-13.txt                   |   +----+---------+-------------------------------------------------+   | 2. | 5       | MIME Definition - added a "SHOULD" statement to |   |    |         | stress that image/tiff is the preferred content |   |    |         | type when representing Profiles S and/or F.     |   +----+---------+-------------------------------------------------+   | 3. | 7       | Revise security considerations.                 |   +----+---------+-------------------------------------------------+   | 4. | 3       | Merged sections2 & 3 and renumbered.           |   +----+---------+-------------------------------------------------+McIntyre, et al.            Standards Track                     [Page 6]

RFC 3950                     image/tiff-fx                 February 2005Authors' Addresses   Lloyd McIntyre   10328 S. Stelling Road   Cupertino, CA 95014 USA   Phone: +1-408-725-1624   EMail: lloyd10328@pacbell.net or          Lloyd_McIntyre@Dell.com   Glenn W. Parsons   Nortel Networks   P.O. Box 3511, Station C   Ottawa, ON  K1Y 4H7   Canada   Phone: +1-613-763-7582   Fax:   +1-613-967-5060   EMail: gparsons@nortel.com   James Rafferty   Brooktrout Technology   410 First Avenue   Needham, MA  02494   USA   Phone: +1-781-433-9462   Fax:   +1-781-433-9268   EMail: jraff@brooktrout.comMcIntyre, et al.            Standards Track                     [Page 7]

RFC 3950                     image/tiff-fx                 February 2005Full Copyright Statement   Copyright (C) The Internet Society (2005).   This document is subject to the rights, licenses and restrictions   contained inBCP 78, and except as set forth therein, the authors   retain all their rights.   This document and the information contained herein are provided on an   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET   ENGINEERING TASK FORCE DISCLAIM 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.Intellectual Property   The IETF takes no position regarding the validity or scope of any   Intellectual Property Rights or other rights that might be claimed to   pertain to the implementation or use of the technology described in   this document or the extent to which any license under such rights   might or might not be available; nor does it represent that it has   made any independent effort to identify any such rights.  Information   on the IETF's procedures with respect to rights in IETF Documents can   be found inBCP 78 andBCP 79.   Copies of IPR disclosures made to the IETF Secretariat and any   assurances of licenses to be made available, or the result of an   attempt made to obtain a general license or permission for the use of   such proprietary rights by implementers or users of this   specification can be obtained from the IETF on-line IPR repository athttp://www.ietf.org/ipr.   The IETF invites any interested party to bring to its attention any   copyrights, patents or patent applications, or other proprietary   rights that may cover technology that may be required to implement   this standard.  Please address the information to the IETF at ietf-   ipr@ietf.org.Acknowledgement   Funding for the RFC Editor function is currently provided by the   Internet Society.McIntyre, et al.            Standards Track                     [Page 8]