10 February 1999: Dave Winer's put out a call for web loggers to work on an XML DTD we can use for sharing information. Here's an almost there DTD for the XML version of More Like This.

This section contains the formal definition of each of the SVG abstract modules as a DTD module.

It’s 9:00 AM on a Monday morning, the boss has called a meeting to discuss a new product as you sit there recovering from a late of night battling foes on the computer you notice your boss has that familiar malicious gleam in his eyes, you know the one it’s the same one he had when he asked if the apps on the server were “508” compliant. As you begin sink in your chair you realize that he is looking at you smiling. He mentions a client and a “Big Opportunity”. Then he mentions the word “Portal” and that is when it dawn’s on you, He has found the stash of “wired” magazines that you have been hiding from him.

One of the keys to XML (and SGML) is the Document Type Definition (DTD), the specification for a particular class of documents. A DTD says what types of elements are meaningful for his type of document, and how they fit together. DTDs are important because they provide a basis for creating and managing whole groups of documents of the same type in a uniform way. This improves the quality of your information, because at least one source of error or confusion has been removed.

Earl Hood's dtd2html generates various HTML files for hypertext navigation of an SGML DTD. The following information is a slightly modified extract from the documentation provided with dtd2html.

This appendix will contain implementations of the modules defined in this specification. These module implementations can be used in other XHTML Family Document Types.

I have been working on this DTD partly out of my interest in using movies as a teaching tool for EFL classes, and partly for practice in developing DTDs. It is in a very early stage of development and is largely untested and entirely undocumented. So if you want to use it, please do so with the understanding that it undoubtedly has a few bugs and omissions, and you'll probably need to hack it a little to get what you want.

Leading the charge into the new year, Paul Miller released version 0.5 of XMLIO, a C library for generating and processing XML streams (with a C++ API as well). Jim Saiya of FormatData released version 0.2 of DESSERT, a DTD for recipes.

This section discusses how the DTD itself is organized. This is mostly of interest to the maintainers of XBEL and any descendent document types that may be defined in the future.

XHTML documents have three parts: the DOCTYPE (which contains the DTD declaration), the head and the body. To create web pages that properly conform to the XHTML 1.0 standard, each page must include a DTD declaration; either strict, transitional, or frameset. Each of the three DTD’s is described (with an example) below:

MathML documents should be validated using the XML DTD for MathML, which is also shown below in Section A.1 [The MathML DTD].

The top-level element for math tagged according to the MathML DTD. See documentation for the Mathematical Markup Language (MathML) 2.0 DTD.

DocBook is a DTD (both SGML and XML versions are available) maintained by the DocBook Technical Committee of OASIS. It is particularly well suited to books and papers about computer hardware and software (though it is by no means limited to these applications).

Structured data conforms to a schema. XML documents are no exception. The XML 1.0 standard defines schema using a subset of SGML's Document Type Definition (DTD). The DTD defines which elements appear in a document, which attributes can be assigned to an element, and which elements appear inside other elements.

GXL has been developed to be an open standard. No licensing or other legal arrangements are required for its use, whether commercial and non-commercial. The specification of GXL is copyright by its authors, to allow control of its evolution. The specification can be reproduced and used without charge, but with explicit acknowledgement of its authors.

We are in the process of formalizing the definition of NeXus files using XML. The hierarchical structure of NeXus files maps very conveniently into XML files with NeXus groups and items as the XML entities, and data attributes as XML attributes. Eventually, we intend to provide utilities to read NeXus files, produce the equivalent XML file, and use standard validation tools to help people determine whether their files are standard-conforming.

Several support files are necessary on your local computer to parse a document tagged according to the Technical Report DTD. These are listed on the previous page. Note: use the downloading instructions listed at the beginning of this page for downloading the files listed here.

This is a snapshot of the Cougar DTD. This is work in progress, subject to change at any time. It does not imply endorsement by, or the consensus of, either W3C or members of the HTML working group. Enclosed are six components which you can extract for use with tools such as James Clark's nsgmlsu which is available as part of the SP package from http://www.jclark.com/sp/index.htm You will need the Unicode version as Cougar uses Unicode for the document character set.

Following is information on the sources of analysis input, the design principles governing the markup model, the implementation principles governing its expression in DTD form, and outstanding issues.

The Document Type Definition (DTD) defines the valid syntax of a class of XML documents. That is, it lists a number of element names, which elements can appear in combination with other ones, what attributes are available for each element type, etc. A DTD uses a different syntax (namely Extended Backus Naur Form) from that used by XML documents.