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NWG/RFC  744                                   JS5 8-Jan-78 21:59  42857Network Working Group                                     Joanne SattleyRequest for Comments: 744                                        JZS@CCANIC: 42857                                                8 January 1978MARS - A Message Archiving & Retrieval ServiceI.    Introduction      ------------This document describes a Message Archiving  and  Retrieval  Service(MARS) which has been developed at Computer Corporation of America; itutilizes the Datacomputer, a network database utility developed by CCAfor  ARPA.   [Research  and development of a prototype MARS system wassupported by the Defense Advanced  Research  Projects  Agency  of  theDepartment  of  Defense,  under the ARPA Very Large Databases program,and was monitored by the Office of Naval Research under  Contract  No.N00014-76-C-0991.]The  Service  is  available,  primarily,  to  groups  for  storage  ofteleconferencing transcripts.  Is is also available, upon request,  toindividual ARPANET correspondents.There  are  both  'public'  and  'private'  messages  in the database.Public messages may be retrieved by  anyone.   The  public  collectionincludes  the  messages of the Header-People [@ MIT-MC] group, and theMsgGroup [@ USC-ISI] proceedings.Private messages may be retrieved only by the users who have  archivedthem,  or anyone whose name appears on the list of message recipients.Messages archived using MARS are heavily indexed and can be  retrievedin  a  variety  of  ways,  including  Boolean  combinations of messagerecipients, message composition date, any text words  in  the  messagesubject,  and text words in the message body.  The MARS facilities areintegrated  very   naturally   into   the   existing   collection   ofmessage-handling tools:   . A message is designated for archiving by sending it to     MARS-Filer @ CCA using one of the usual message-mailing tools such     as SNDMSG.   . A message is designated for retrieval by sending a request as     ordinary mail to MARS-Retriever @ CCA.The  Filer  program  checks for mail every hour; the Retriever programchecks every quarter-hour.  The periodicity can  be  altered  to  meetdemand  but  the intent is for MARS to operate as a background job andonly during extremely low-activity periods.The next section (II) describes  the  indexing  operation  in  greaterdetail,  and  how  to archive and retrieve messages.  The last section(III) is an extractable user card.                                                                [Page 1]

NWG/RFC  744                                   JS5 8-Jan-78 21:59  42857MARS - A Message Archiving & Retrieval ServiceII.       Using MARS          ----------A.  Message Indexing    ----------------For each message, a vector of parsed tokens is  created.   The  parsedtokens are collected by the message-field in which they occurred -- tobe  used  as  "indexes",  i.e.,  values  of  inverted  fields,  by theDatacomputer.The Filer "indexes", essentially  without  analysis,  except  for  thefollowing:   --  Each distinguishable section of the message is indexed       separately; each header line is a separate inversion domain, as       is the body of the message.   --  The header lines which contain ARPANET addresses are analyzed in       order to index separately on mailbox and host.   --  The date-field is parsed and converted to the standard Tenex       internal date/time format, which is better adapted for       less-than/greater-than comparisons, as in retrievals which       specify a date range.   --  One-character words in both the subject-field and the       message-text field arbitrarily discarded.   --  Two-character words in the message-text field are arbitrarily       discarded.   --  Hyphenated phrases, i.e., words bound together by hyphens, are       retained intact.   --  All message formats which conform to RFC  733 standards are       accommodated.  The minimum requirements are:  a date-field, a       from-field, and a blank line between the message-header and       message-body.                                                                [Page 2]

NWG/RFC  744                                   JS5 8-Jan-78 21:59  42857MARS - A Message Archiving & Retrieval ServiceB.  To Archive Messages    -------------------There  are  three modes of filing currently supported by MARS, to wit:   --  single-message mode, wherein the MARS-Filer mailbox appears in       the message as an addressee;   --  forwarded-message mode, wherein the MARS-Filer mailbox appears as       the only primary recipient;   and   --  batch mode, wherein the mailing envelope is addressed to       MARS-Filer and the subject-field contains the keyword "batch".Until the ARPANET standard for the format of messages  is  implementeduniversally, the variability amongst formats is still greater than theFiler can handle as it stands.  Nonetheless, a user  can  successfullyfile  any  message in a "foreign" format by forwarding it to the Filerunder the aegis of a mail-handling program  which  does  produce  goodformats.   Admittedly, the correct header-field indexing, as describedabove, will not be done on the enclosed message;  but  at  least,  thewords  in  its unreadable header fields will appear as "text" words inthe indexing.In the case of forwarded-message-mode filing, all interesting indexinginformation is extracted from the  message-header  of  the  forwardingenvelope  prior  to discarding it.  The name of the archiver, the dateand time the message was forwarded, and the  subject-line  informationare   recorded.   The  remainder  is  handled  as  though  it  were  anon-forwarded message which had been CC'd to the Filer.A forwarded message may be 'annotated' by adding  text  (e.g.,  notes,comments, keywords) in the forwarding envelope.  Annotations are filedand retrieved as part of the archived message.In  the  case  of  batch-mode filing, only the archiver's name and thedate and time s/he sent the package are  extracted  from  the  mailingenvelope.   The  message-body  portion  is then treated as a series ofindividual messages.                                                                [Page 3]

NWG/RFC  744                                   JS5 8-Jan-78 21:59  42857MARS - A Message Archiving & Retrieval ServiceC.  To Retrieve Messages    --------------------Retrievals are initiated by sending a Retrieval Request  (which  is  aspecially   formatted  message)  to  "MARS-Retriever@CCA".   Retrievedmessages are mailed back, one at a time, and will appear as  new  mailin the requester's mailbox.Retrieval  Request  messages  can be composed using any SNDMSG-type ofprogram, as follows:   . The recipient of the RR message must be MARS-Retriever @ CCA   . Other message header fields are ignored for now   . The message body portion of the RR is used to compose Datalanguage     for performing the retrieval.  Its format resembles a message     header, or selected portions thereof.The following list defines which field names are recognized, and  somenotes  on  their  interpretation.   The  scanning  of  each  field  isterminated by a carriage-return.   DATE:     The format of the date field is day-month-year.  Use of             hyphens is optional.  This field will cause  only those             messages composed on the specified date to be retrieved.   AFTER:    Use of this field will  retrieve  messages  composed after             the specified date.   SINCE:    This field is interpreted like the AFTER: field.   BEFORE:   Use of this field will  retrieve  messages  composed before             the specified date.   UNTIL:    This field is interpreted like the BEFORE: field.   FROM:     This field is expected to contain  a  valid  mailbox name.             The host specification is optional.  If more than one name             is specified, ORing of  the  names  is implicit.             Retrieval  based upon host specification alone has not been             implemented.   TO:       This field is expected to contain one or more  valid             mailbox  names.  The host specification is optional. Spaces             and commas between the names imply AND.                                                                [Page 4]

NWG/RFC  744                                   JS5 8-Jan-78 21:59  42857MARS - A Message Archiving & Retrieval Service   SUBJECT:  Use of this field will retrieve all  messages  whose             indexed  subject-field  contents match the specified             word(s).  Spaces and commas imply AND.  The  use  of OR             must be explicit.   TEXT:     Use of this field will retrieve all  messages  whose             indexed  message-body  contents  match the specified             word(s).  Spaces and commas imply AND.  The  use  of OR             must be explicit.An  interactive  TENEX-based  program  for composing RRs is available;the filename is "RR.SAV".  A copy of this program  is  stored  on  theDatacomputer, available via DFTP under node COMMON>MARS.There  is  also  a  copy  of the program in CCA's directory at SRI-KA;another in the CCA-ACCAT directory at ISIA.                                                                [Page 5]

NWG/RFC  744                                   JS5 8-Jan-78 21:59  42857MARS - A Message Archiving & Retrieval ServiceIII.      MARS User Card          --------------::  Archiving    ---------Individual Messages   . Include MARS-Filer@CCA on message distribution list   . Forward message to MARS-Filer@CCA [Annotation is optional.]Batches of Messages   . Incorporate the mail file as the message-body of a single     message sent to MARS-Filer@CCA with the clue "BATCH" in its     subject-field.::  Retrieving    ----------Using RR Program   . RR is a TENEX-based interactive program designed to prepare     Retrieval Request messages and to mail them to MARS-Retriever@CCA.Using SNDMSG-Type Program   . Send a message to MARS-Retriever@CCA, specifying the retrieval     criteria in the body of the message.Sample Retrieval CriteriaSUBJECT:RFC 733 orRFC733     ; OR must be explicitTEXT:MARS Project,goals       ; spaces & commas imply ANDDATE: 14 November 1977SINCE: 1 Nov 77               ; same as AFTER: 1 Nov 77AFTER: 1  Dec 1977UNTIL: 15 January 1978        ; same as BEFORE: 15 January 1978BEFORE: Aug 7 76FROM:  JZS@CCA         ; host specification is optionalFROM:  Hacker,JZS      ; comma implies OR (in FROM: field only)TO:  CCA@SRI-KA     ; host specification is optionalTO:  SDD-0:,SDD-1:  ; spaces and commas imply AND                                                                [Page 6]