CURRENT_MEETING_REPORT_ Reported by Greg Vaudreuil/CNRI Minutes of the Internet Message Extensions Working Group (822EXT) The Internet Message Extensions Working Group met twice in Columbus to review and approve the MIME protocol for submission as a Draft Standard. With a handful of changes, the MIME protocol was approved. The Working Group agreed to disband after publication of the revised document. Several new working groups will be formed to define extensions to the MIME protocol and additional content-types. The solutions listed in the latest MIME issues list, as distributed periodically to the IETF-822 mailing list, were accepted with the following additions and changes: o Encoding of Content-Type Message RFC1421 prohibits the use of a content-transfer-encoding other than 7bit, 8bit, and Binary on the message type. This was designed to ensure that both the structure of a MIME message is visible without decoding and that nested encodings were not generated. Implementation experience has uncovered several problems with the use of message/partial and message/external-body when conversion is required in a gateway. In particular, using a non-null of a partial 8 bit message for 7 bit transport is prohibited. Even if it was allowed, re-encoding the message into a 7 bit encoding would be likely to cause message size growth, defeating the intent of using message partial in the first case. The question for the Group was whether to limit encoding of any message type to 7 bit or only message/partial. The Group agreed to modify the prohibition to allow only content-transfer-encoding of 7bit for the message/partial content-type. o Representation of Filenames in Message/External-body The inclusion of filenames in the content-type headers has the effect of requiring that all filenames be 7 bit ASCII. The Working Group discussed the likelihood that new operating systems will require a richer character set for filenames and the possibility that when this occurs the current filename mechanism may not be adequate. After lengthy discussion during which the Group considered the possibility of using an encoded word from RFC1342, it was agreed that no changes should be made at this time and that when needed a new content-type could be defined with an enhanced mechanism. o Definition of Charset The Working Group agreed to significantly trim the definition of a character set and to eliminate specific wording about specific unregistered character sets. The discussion of specific character 1 sets not currently listed with IANA was eliminated, (see the revised document for the new wording). Agreement was reached to remove Appendix F.2, the procedure for IANA registration, in favor of a statement pointing to the IANA for the procedure. It is expected that this procedure will evolve independently of MIME. Issues related to the application of the general principle of a ``charset'' to specific current and future character sets is not part of the Charter of this Working Group and will be the subject of a new working group chartered to address the character set issues in a more general IETF context. o MIME-Version: 1.0 Header Semantics The Working Group discovered that the MIME-Version header was insufficiently defined to be used for true versioning and that the interpretation of this header was not uniform across current implementations. Understanding that backward compatible changes to MIME were unlikely and that changing the version in the current header will cause at least one implementation to fail to recognize the message as valid MIME, the Working Group agreed that this header should now be considered a string constant; any version specific notes should be encoded as an RFC822 comment in the MIME-version header line, a feature available in all other RFC822 headers. Attendees Harald Alvestrand Harald.Alvestrand@delab.sintef.no Gabe Beged-Dov gabe@cv.hp.com Nathaniel Borenstein nsb@bellcore.com Kevin Carosso kvc@innosoft.com George Chang gkc@ctt.bellcore.com William Chung whchung@watson.ibm.com James Conklin jbc@bitnic.educom.edu Al Costanzo al@akc.com Urs Eppenberger eppenberger@switch.ch Erik Fair fair@apple.com Roger Fajman raf@cu.nih.gov Ned Freed ned@innosoft.com James Galvin galvin@tis.com Christine Garland garland@ihspa.att.com Terry Gray gray@cac.washington.edu Alton Hoover hoover@ans.net Jeroen Houttuin houttuin@rare.nl Marko Kaittola Marko.Kaittola@funet.fi Neil Katin katin@eng.sun.com John Klensin klensin@infoods.unu.edu Jim Knowles jknowles@binky.arc.nasa.gov Mary La Roche maryl@cos.com Keith Moore moore@cs.utk.edu Masataka Ohta mohta@cc.titech.ac.jp Emmanuel Pasetes ekp@enlil.premenos.sf.ca.us 2 Francois Robitaille francois.robitaille@crim.ca Marshall Rose mrose@dbc.mtview.ca.us Carl Schoeneberger 70410.3563@Compuserve.com Gregory Sheehan gregory.c.sheehan@att.com Einar Stefferud stef@nma.com Gregory Vaudreuil gvaudre@cnri.reston.va.us 3