CURRENT_MEETING_REPORT_

Reported by Tom Magliery/NCSA

Minutes of the MIME Content-Type for SGML Documents Working Group
(MIMESGML)

This group met as the SGML BOF at the 31st IETF on 6 December, and has
since become the MIMESGML Working Group.


Goal

The primary goal of this meeting was to establish a working group to
propose a standard for SGML document exchange over the Internet; i.e.,
to propose a MIME encapsulation for SGML (beyond ``text/sgml'').


Agenda

   o Introduction
   o Statement of goals
   o Discussion of charter for group
   o Discussion of a list of issues facing the group
   o Creation of a calendar of milestones for the group


Discussion

A draft charter is being discussed by the IESG (Internet Engineering
Steering Group) and may be issued the week of 12 December 94.

Ed Levinson gave a brief introduction to the proposal contained in his
Internet-Draft, draft-levinson-sgml-02.txt.  He showed how Content-IDs
are used as interchange tokens for file names in SYSTEM entities.

Paul Grosso, gave a brief introduction to the parts of SGML relevant to
the working group's charter.  He also described the SGML Open Technical
Committee Report TR 9401 which recommended the inclusion of a catalog
with SGML exchange packages.

A discussion ensued about providing a catalog similar to the one the
SGML Open Technical Resolution 9401:1994 describes in issue B. The
catalog would allow for a single place for the mapping of logical names
to actual storage object locations.  An SGML Open style catalog allows
for the mapping of PUBLIC identifiers into their respective storage
object identifiers and helps the receiving system resolve the PUBLIC
identifiers.  The need for the catalog was questioned and the exact MIME
message format was discussed.  No consensus was reached on these issues,
and a suggestion was made to conduct further discussions on this topic
via e-mail.

Two other issues were discussed in detail, the number of parts to
separate the SGML document into, as body parts in the MIME message and
the MIME content-type to be used.  As to the number of parts, the
Internet-Draft, draft-levinson-sgml-02.txt, proposed three parts, the
SGML Declaration, the prolog, and the document instance.  That allowed
for the possibility of SGML viewers that required those parts to be
provided separately rather than as a single stream.  Charles Goldfarb
noted that SGML is defined as a stream and, since a default declaration
exists, a single part, consisting of the prolog and instance suffices.
Others pointed out that HTML, used for the World Wide Web, could likely
use a similar scheme, especially upon achieving full SGML compliance.
The attendees reached consensus on using two parts, not three.

Tim Bernards-Lee suggested using a Multipart/Related content type
instead the Multipart/SGML, as proposed in Ed Levinson' Internet-Draft.
The first body part in the Multipart/Related being the beginning of the
document.  Discussion was deferred to allow the group to identify all
the issues of concern.

The issues below were identified and then categorized as being
controversial, non-controversial, and not within the working group scope
or charter.  Ed Levinson agreed to start discussions of each
controversial topic.


List of Issues

The following is a list of some of the issues we decided the group needs
to consider.

Legend:


``*'' -- Issues needing to be resolved through discussion
         (or strong differences of opinion exist)
``o'' -- Plain old ordinary issues (no strong differences exist)
``-'' -- Related issues that do not need to be tackled by this working
         group


    * MIME content types
      application/sgml versus text/sgml
      multipart/sgml versus multipart/mixed

    * Use of Content-ID
      Content-ID implies the receiving system may cache the body part.
      Should an new header be used, i.e.  Content-reference?

    * URIs, should we used a URL style for the content-ID label (i.e.,
      cid:...)?

    o Catalog
      Should one be explicitly included?

    o SDIF (SGML Document Interchange Format)
      Should the Proposed Standard include the section on SDIF now in the
      Internet-Draft?

    o Ordering of SGML document parts in multipart MIME parts:  is it
      required?

    o Should the SGML document be transported in three parts
      (declaration, prolog, instance) or two, (prolog and instance
      combined as one).

    o Character sets:  how to deal with documents with multiple languages
      and how to specify the markup character set.

    o Security implications
      Processing Instructions and NOTATION SYSTEM identifiers.

    - Style sheet support
      Only need to show how to extend work to include style sheets.

    - SGML fragments
      Sending a part of a document along with information on where in the
      content model parse tree it belongs.  ``Swiss cheese'' or
      incomplete documents.


Milestones/Calendar

 December 94:            Establish an IETF working group (should happen 
                         this week).
 February 95 (3rd week): Internet-Draft available.

 March 95:               SGML Open Technical Committee meetings/review of 
                         draft.
 April 95:               Proposed Standard.

 May 95:                 Last Call on Proposed Standard.


Further Information

There is a mailing list appropriate for discussion of these issues.  The
mailing list address is sgml-internet@ebt.com.  To subscribe to the
list, send e-mail to majordomo@ebt.com with the body subscribe
sgml-internet.

There may or may not be an archive of the mailing list; Paul Grosso will
be checking on this.  (Even if there is not one yet, the list really has
not received any traffic, so nothing has been lost.)