ISO/IEC JTC1/SC18/WG8 N

    Title:                Second Interim Report on the Project
                          Editor's Review of ISO 8879

    Source:               SGML SWG

    Project:              1.18.15.1

    Project editor:       C. F. Goldfarb

    Status of document:   Approved report

    Requested action:     For information

    Date:                 22 April 1994

    Distribution:         WG8 and liaisons

ISO 8879 (SGML) was published in October 1986, and in 1991 was subject
to the formal 5-year review ballot required of all ISO standards.  The
ballot reaffirmed ISO 8879 (source:  SC18 N3128).  With this support,
WG8 directed the Project Editor to conduct a systematic review of the
standard to consider future development.

                       I. Principles and policy

WG8 has agreed to a set of principles for any future development
(JTC1/SC18/WG8 N1289).  These principles ensure that all existing
conforming SGML documents will continue to conform after any changes
are made to the standard.

WG8 has also adopted a policy for the review (JTC1/SC18/WG8 N1350).
The review process ensures that every clause, paragraph, note, and
syntax production of ISO 8879 is reviewed.

                        II. Review activities

The review is structured in two related activities:

Activity 1. Information described by SGML markup

The objective of this activity is to define explicitly the information
described by the SGML syntax and to group it, as appropriate, into
useful "information sets", such as the Element Structure Information
Set (ESIS) (see annex A of ISO/IEC DIS 13673).

Activity 2. Proposed changes to ISO 8879

The objective of this activity is to identify changes required to
correct or enhance the text of ISO 8879, and to publish a revised
edition of the standard that incorporates those changes and the
changes made by Amendment 1 (1988).

The activity will be conducted in the following sequence:

1. Evaluation of submitted comments

This step is occurring concurrently with Activity 1.

Comments, in the form submitted, are reviewed at a meeting of
the WG8 SGML Rapporteur Group, which prepares a response to the
submitter. The response classifies the comment in terms of whether it
identifies a requirement that should be addressed by a revision of the
standard:

A) Does not identify a requirement that should be addressed.

Such responses typically include a clarification of a misunderstanding
or an erroneous or contradictory assumption of the applicant.

B) Identifies a requirement that should be addressed.

C) Will be studied further during the clause-by-clause review.

From time to time the RG may add class B comments to a published list
of requirements expected to be satisfied by the revision of SGML.  The
failure of a comment to be added to this list, however, does not
preclude it being included in the final list of requirements to be
satisfied (see step 3, below).

2. Clause-by-clause examination of the standard

This step will begin when a complete draft of Activity 1 has been
created.  It will result in more additions to the list of requirements
expected to be satisfied by the revision of SGML.

3. Member Body approval of requirements to be satisfied

The list of requirements generated by the earlier steps will be
reviewed for technical accuracy.  A final list of "Requirements to be
Satisfied by the Revision of ISO 8879", including the expected changes
needed to satisfy the requirements, will be submitted for Member Body
approval.  Also submitted will be the reasons why the list fails to
include any requirement that had previously been identified as a
requirement expected to be satisfied.

4. Preparation and balloting of text of changes

Text will be prepared for the changes needed to satisfy the approved
requirements and will be ballotted in accordance with ISO directives.

5. Publication of revised ISO 8879

Upon approval of the text of the changes, the changes will be
incorporated into the text of ISO 8879, together with Amendment 1, and
the integrated text will be published.

              III. Status of the Project Editor's review

Three papers have been prepared for Activity I:

N1710 documents the "Class and Object Model Vocabulary" that we use in
defining the information that SGML markup describes.

N1711, "Information Described by SGML Markup" is a first attempt
(incomplete) to create that definition, using the terminology of
N1710.

N1712 is the starting point for our consideration of "Document
Addressing Methods Used by SGML Applications", including those in
existing and proposed WG8 standards.  Our objectives include
facilitating precise and unambiguous definition of addressing methods,
and facilitating transforms among them.

The review has progressed sufficiently that we can state that changes
will be recommended.  In order to acquaint the SGML community with the
types of change we are contemplating, we published an initial list of
requirements expected to be satisfied by a revision of ISO 8879,
together with associated changes (if any) in May, 1993 (WG 8 N????).
An additional list is included in this report.  Please note that the
list is by no means complete with respect either to the set of
requirements or the possible changes associated with each requirement.
Nor do we believe it to be statistically representative of the changes
that we will eventually recommend.

The new list items follow, in no particular order:

Requirement: To support multi-byte character sets with greater
convenience

1. We will devise a less burdensome method for declaring long
sequences of character numbers.

Requirement: To facilitate name-space modularization in DTDs and LPDs