ISO/IEC JTC1/SC18/WG8 N1289

TITLE:	Future development of ISO 8879
SOURCE:	WG8
PROJECT:	1.18.15.1
PROJECT EDITOR:	C. F. Goldfarb
STATUS OF DOCUMENT:	Agreed WG8 Position
REQUESTED ACTION:	For information
DATE:	7 May 1990
DISTRIBUTION:	WG8 and Liaisons

The future development of ISO 8879 shall be consistent with the following principles:

Any document that is a conforming SGML document according to the current standard shall continue to be a conforming document under the provisions of future versions of the standard.
The results of parsing an SGML document (that is, the element structure information set, or "ESIS") that conforms to the current standard shall be unchanged when the document is parsed under the provisions of future versions of the standard.
A document that is classified as a minimal or basic conforming SGML document under the current standard shall continue to be classified as such under the provisions of future versions of the standard.
NOTE 1 -- These principles should not be construed to mean that no changes can be made to ISO 8879. To meet evolving user requirements, for example, some changes of the following types are possible without violating the above principles:
- Relaxing restrictions
- Adding new constructs
- Partitioning existing optional features
- Introducing options to allow the suppression of troublesome existing constructs, when experience indicates that the constructs tend to induce user errors with serious consequences
Future versions of the standard shall require conforming SGML parsers and systems to support conforming SGML documents, minimal conforming SGML documents, and basic conforming SGML documents to at least the same extent as the current standard.
NOTE 2 -- Future versions of this standard can introduce additional requirements as well.

NOTE 3 -- These principles should not be construed to mean that the definition of a "conforming SGML document" cannot be changed, only that existing conforming SGML documents will continue to be classified as such.