The purpose of a DTD is to define the legal building blocks of an XML document. It defines the document structure with a list of legal elements. A DTD can be declared inline in your XML document, or as an external reference.

This section covers some XML and DTD examples.

This is a draft of Wikipedia DTD, an interchangeable XML representation of the content of wikipedia articles. It contains elements for the content of an article (Wikitext DTD). This is also a contribution to get a formal wikitext standard that is still lacking. When there is such a standard multiple suites of software (some based on mediawiki, some not) could support it, and each Wikipedia could choose between them, while supporting the same portable open content.

The 2001-08-20 IETF document iCalendar DTD Document (xCal) defines an XML Document Type Definition (DTD) that corresponds to the iCalendar, Internet Calendaring and Scheduling Core Object Specification defined by RFC 2445. This DTD provides equivalent functionality to the standard format defined by RFC 2445. Documents structured in accordance with this DTD may also be known as 'XML iCalendar' documents or 'xCal'.

The purpose of this committee [OASIS DocBook Technical Committee] is to develop and maintain the DocBook family of specifications. In particular, this TC maintains the XML and SGML DocBook DTDs, a suite of extension modules, and a simplified authoring subset of DocBook. The TC may also support other schema languages in the future and may develop additional modules and derived document types. The DocBook TC will also develop specifications based on previously published standards for use in the XML version of DocBook and other related XML specifications; the first such specification will be based on previously published ISO 9573 entity sets (themselves an extension of the ISO 8879 entity sets). [Revised OASIS DocBook TC Charter, 2001-08-23]

This section describes what DTD-Entities are.

This section uses the Echo program to see what happens when you reference xhtml.dtd in slideshow.dtd. It also covers the kinds of warnings that are generated by the SAX parser when a DTD is present.

After the XML declaration, the document prolog can include a DTD, which lets you specify the kinds of tags that can be included in your XML document. In addition to telling a validating parser which tags are valid, and in what arrangements, a DTD tells both validating and nonvalidating parsers where text is expected, which lets the parser determine whether the whitespace it sees is significant or ignorable.

The Simplified DocBook DTD is a small subset of the DocBook XML DTD. The online summary shows just how small this subset is.

Xerlin is an extensible XML editor. For a particular XML tag you can create a custom editor frame to be displayed to the user. Xerlin comes with its own default editor that allows modification of the attributes according to the DTD, this may be sufficient for your requirements but Xerlin also allows you to specify GIFs to be associated with each XML tag.

XHTML modules are implemented as DTD fragments. When these fragments are assembled in a specific manner (described in Developing DTDs with defined and extended modules), the resulting DTD is a representation of a complete document type. This representation can then be used for validation of instances of the document type.

MathML documents should be validated using the XML DTD below. Note in particular that the xml attribute xml:space is not used, so whitespace characters in element content (ie. outside the presentation token elements mi, mo, mn, mtext, mspace, mtext, ms , the content token elements ci, cn and annotation) are not significant.

This material can serve as a lean reference source for the elements in the dtds. They provide the nesting structure and content models for the dtds.

The workshop opened with comments by J. McDonough (NYU) regarding the origins and purpose of the workshop. University research libraries that have begun to create digital collections have encountered some common problems surrounding metadata and encoding for digitized versions of primary source material, including:

The metadata compiler I have developed can produce output in Standard Generalized Markup Language (SGML), a structured system for making complex textual documents interpretable by computer software. In order to use the SGML output of the compiler, however, you need an SGML parser or software that includes one and a document type definition (DTD) that instructs the parser about the document at hand. The DTD is essentially a reexpression in SGML of the syntactical rules given in the FGDC Content Standards for Digital Geospatial Metadata.

We study the inference of Data Type Definitions (DTDs) for views of XML data, using an abstraction that focuses on document content structure. The views are defined by a query language that produces a list of documents selected from one or more input sources. The selection conditions involve vertical and horizontal navigation, thus querying explicitly the order present in input documents. We point several strong limitations in the descriptive ability of current DTDs and the need for extending them with (i) a subtyping mechanism and (ii) a more powerful specification mechanism than regular languages, such as context-free languages.

This document provides a description of the extensions to xmlspec developed specifically to support the creation of i18n techniques. NOTE: this is all subject to constant change.

In a way proprietary features are such features, which belong to the specifications, but implementations broke in purpose existing specifications. New MS IE and Netscape/ Mozilla browsers use DTD-switches, when with certain without DTD or with certain DTD new browsers work in some matters at the same way as older and more buggy browsers.

This is the documentation website for the Blackwell Publishing XML DTD version 4.0.

Elements are the basic building blocks of DTDs. An element has at least a name and a definition of what kind of content it can contain.