by Martin Bryan, The SGML Centre
[Note: Martin Bryan sits on the SGML Users' Group delegation to WG8]
The last few months have been very important for SC18/WG8. In December 1995, ISO finally published ISO 10180, which defines the Standard Page Description Language (SPDL). At the same time the final editorial touches were made to the Document Style Semantics and Specification Language (DSSSL) and this was sent to ISO for publication. ISO published this last member of the SGML standards set on April 1st 1996 as ISO 10179. At long last the SGML community has an integrated set of standards to work with -- the result has been well worth waiting for!
As part of the process of getting DSSSL published, it was necessary to standardize the way SGML properties are referenced in HyTime and DSSSL. At the WG8/SC18 meeting held in Broomfield, Colorado, in October much time was spent in reviewing the SGML property set in ISO 10744 (HyTime) and identifying what additional functionality was required to support both the SGML Document Query Language (SDQL) used in DSSSL and any future extensions to SGML. It was determined that those facilities of HyTime that are of relevance to any SGML application, such as the formal description of property sets, should be taken out of the main text of ISO 10744 and placed in a General Facilities annex that could easily be referenced from within DSSSL and other standards related to SGML. This annex will also contain a formal definition of an SGML grove (Graphical Representation of property ValuEs). Groves are a fundamental concept of both HyTime and DSSSL which will provide a formal mechanism for ensuring that extensions to, and applications of, SGML can provides access to all of the information in the markup and data content of an SGML document, including data defined in SGML architectural forms.
Another area in which SGML, DSSSL and HyTime have been harmonized is through an extension to the system identifier syntax to allow Formal System Identifiers (FSIs) to be used alongside Formal Public Identifiers. A formal specification of the syntax of FSIs will be published as part of the General Facilities annex.
As the SGML Document Query Language (SDQL) defined in ISO 10179 now includes the functionality the HyQ query language initially provided in HyTime it has been agreed that ISO 10744 will be revised to replace HyQ with SDQL as the standard query option within HyTime.
At the Broomfield meeting the committee looking into enhancements to SGML also discussed how the SGML declaration could be extended to improve the way in which large character sets, such as those required for oriental languages, could be used as part of an SGML name, etc. A thorough review of language related issues is to be undertaken before the SGML declaration is enhanced.
It has been agreed that future WG8/SC18 meetings will be held in conjunction with the GCA SGML conferences so that members of the committees can get more input from users. The next WG8/SC18 meeting will be held immediately after SGML Europe 96. Most of those attending the ISO meetings will be at the conference, which will give you a chance to air your thoughts on how SGML and its related standards can be improved. In suggesting improvements, however, it is vital that you bear in mind the tight integration between SGML, HyTime, and DSSSL . Suggestions for one of these standards should consider the impact on the other two. We would recommend a thorough study of all three standards by all involved in generating or using SGML documents. In any case, let us know your requirements.
Martin Bryan
The SGML Centre
Churchdown, Glos.
GL3 2PU, UK
Phone/Fax: +44 1452 714029
WWW home page: http://www.u-net.com/~sgml/
