Markup encodes a description of the document's storage layout and logical structure. See now the separate document for references to SGML/XML FAQs.XML provides a mechanism to impose constraints on the storage layout and logical structure. This document cites the earlier versions of the XML FAQ (1.5, 1.4, 1.3, 1.2, 1.1) and early translations into Japanese, Spanish, and Korean.A new Netsape document describes how to apply MCF using XML, the Extensible Markup Language." Links: On January 5, 1998, a new (revised) submission on XML-Data was presented to the W3C by Microsoft, Arbor Text, Data Channel, and Inso. Authors: Andrew Layman, Edward Jung, Eve Maler, Henry S. It can be used for classes which as strictly syntactic (for example, XML) or those which indicate concepts and relations among concepts (as used in relational databases, KR graphs and RDF).The former are called 'syntactic schemas;' the latter 'conceptual schemas.' The text of this NOTE thus "provides a specification (XML-Data) for describing and exchanging structured and networked data on the Web.These working groups were designed to have close liaison relationships with the W3C's Extensible Style[sheet] Language (XSL) Working Group and Document Object Model (DOM) Working Group."Extensible Markup Language, abbreviated XML, describes a class of data objects called XML documents and partially describes the behavior of computer programs which process them.It is also expected to find use in certain metadata applications.
The W3C XML WG has published a technical NOTE providing a "detailed comparison of the additional restrictions that XML places on documents beyond those of SGML": see for the details. (XML Co-editor); Dan Connolly, W3C; Steve De Rose, INSO; Dave Hollander, HP; Eliot Kimber, Highland; Eve Maler, Arbor Text; Tom Magliery, NCSA; Murray Maloney, Muzmo and Grif; Makoto Murata, Fuji Xerox Information Systems; Joel Nava, Adobe; Peter Sharpe, Soft Quad; John Tigue, Data Channel." Historically: The W3C SGML Editorial Review Board, as of November 5, 1996, had the following members: Jon Bosak, Sun ([email protected]), chair; Tim Bray, Textuality ([email protected]), editor; James Clark ([email protected]), technical lead; Dan Connolly ([email protected]), W3C contact; Steve De Rose, EBT ([email protected]), editor; Dave Hollander, HP ([email protected]); Eliot Kimber, Passage Systems ([email protected]); Tom Magliery, NCSA ([email protected]); Eve Maler, Arbor Text ([email protected]); Jean Paoli, Microsoft ([email protected]); Peter Sharpe, Soft Quad ([email protected]); C. These specifications are being developed by various working groups, sometimes as part of activity outside the sphere of the XML Activity. Some already play a vital role in profitable commercial enterprise.
The NOTE also includes an SGML declaration which describes the constraints of XML applicable to an SGML parser. It is also to be expected that some early XML/XLink/XSL applications may be merely demonstrations, toys, proof-of-concept applications; still others might be naive or ill conceived.
[local archive copy] [This paragraph is superseded by the technical NOTE 'NOTE-sgml-xml' referenced immediately above.] Features in SGML but not in XML include [as of November 5, 1996]: "Tag omission; The CONCUR, LINK, DATATAG, and SHORTREF features; The "&" connector in content models; Inclusions and exclusions in content models; CURRENT, CONREF, NAME, NAMES, NUMBER, NUMBERS, NUTOKEN, and NUTOKENS declarations for attributes; The NET construct; Abstract syntax; Capacities and quantities; Comments appearing within other markup declarations; Public Identifiers; Omission of quotes on attribute values." For a more recent/complete comparison of features, see the relevant section in the language specification, or "What else has changed between SGML and XML? As of December 1997, the current and former members of the XML WG are: "Jon Bosak, Sun (Chair); James Clark (Technical Lead); Tim Bray, Textuality and Netscape (XML Co-editor); Jean Paoli, Microsoft (XML Co-editor); C. It may be necessary to regard some of these ideas 'in draft' like some of the specifications documents themselves. [June 30, 1999] A 'TEI Lite DTD in XML' was made available from the TEI Web site.
Such exchange is facilitated by schemas defining the characteristics of classes of objects.
The objects can be syntactic constructs such as are used in XML instances, or may be more abstract such as are found in databases, information models or directed, labeled graphs.