ISO Subcommittee 34 (ISO/IEC JTC 1/SC34, Information Technology: Document Description and Processing Languages) has released a first working draft for DSDL. Edited by Martin Bryan, the draft 'Document Schema Definition Language' (DSDL) "allows the definition of document structures, data types and data relationship constraints that can be applied to data represented using the ISO/IEC 8879 Standard Generalized Markup Language and its derivatives, such as ISO/IEC 10744, Hypermedia/Time-based Structuring Language (HyTime), and the W3C Extensible Markup Language (XML). A new, compact, efficient and XML-based document type definition for the integrated description of document structures, data types and data relationships will make it possible to automate the processing of structured information resources to the level required by business users, which has a higher level of requirements than those identified from the publishing community for which SGML was originally developed. The standard will also define the scope and notation for converting and interworking a core subset of document structure, data type, and data relationship constraint models among the three notations: DSDL, DTD declarations and XSD. Informative Annex 4 of the draft ['Alphabetical List of DSDL Components'] supplies (1) a list of DSDL components common to SGML and XML, viz. DSDL components which can be used to describe documents conforming to the WebSGML subset of ISO/IEC 8879, and (2) DSDL components specific to SGML, viz. extensions which could be made if it is decided that DSDL should be able to express all constructs in SGML document instances as well as the WebSGML subset.

From the draft Introduction: "SGML Document Type Definitions (DTDs) allow document structures to be formally modelled but do not allow details of data types or data relationships to be recorded in an XML-compatible way. While the W3C XML Schema Definition language (XSD) does allow data types to be used to validate the contents of SGML elements and values of attributes, it does not allow the relationships between the values of different attributes and contents of elements to be validated. A new, compact, efficient and XML-based document type definition for the integrated description of document structures, data types and data relationships will make it possible to automate the processing of structured information resources to the level required by business users, which has a higher level of requirements than those identified from the publishing community for which SGML was originally developed. The standard will also define the scope and notation for converting and interworking a core subset of document structure, data type, and data relationship constraint models among the three notations: DSDL, DTD declarations and XSD."

Status: "[The document N264] is a "submission from the UK of an initial Working Draft for the Proposed DSDL standard that identifies users requirements for the proposed standard in Annex 1. This document is submitted as originally supplied and although the User Requirements are contained in an annex which is marked as normative, the UK does not consider that these requirements, which are instructions to the Project Editor, should remain as normative requirements on the users of the published standard. SC 34 may like to consider whether these requirements should be contained in a separate User Requirements document that could form definitive instructions to the editor... This document was included in the NWI comments, but the U.K. intended to have it distributed separately in its entirety to serve as a base document for further development."

First Working Draft bibliographic information: "U.K. National Body Contribution to First Working Draft of Document Schema Definition Language (DSDL)." Document: ISO/IEC JTC 1/SC34 N264. 22-October-2001. First Working Draft. Edited by (Project Editor) Martin Bryan. Source provided by G. Williams, UK NB. From the activity of ISO/IEC JTC 1/SC34 Information Technology -- Document Description and Processing Languages.

Contact: Dr. James David Mason (ISO/IEC JTC1/SC34 Chairman); Y-12 National Security Complex, Information Technology Services, Bldg. 9113 M.S. 8208, Oak Ridge, TN 37831-8208 U.S.A. Telephone: +1 865 574-6973. Facsimile: +1 865 574-1896. E-mail: mxm@y12.doe.gov. WWW: http://www.y12.doe.gov/sgml/sc34/sc34oldhome.htm.