This DTD is intended to allow both new standards to be edited and legacy data to be handled. Therefore it has to cope with all the different ways the standards were written in the last couple of decades. Thus the DTD is intentionnally lax. It is VERY flexible.

SGML is the substratum on which HTML was conceived and, therefore, is responsible for many of HTML's strengths and weaknesses. SGML stands for Standard Generalized Markup Language; this is a formal system designed for building text markup languages. It is not a markup system by itself, however; think of it as a programming language to build working programs (HTML being one of them) rather than a program by itself.

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

Why a DTD for Ant ? Because good XML editors (such as Emacs with PSGML) can ease build.xml files writing only if a DTD can be parsed. For instance, Emacs + PSGML indicates possible elements for a point in a file, prompts for mandatory attributes (in the minibuffer), etc. So a DTD is nice.

This page contains instructions for downloading Version 2002 of the Document Type Definition (DTD) for the Encoded Archival Description, an implementation of ISO 8879, SGML (Standard Generalized Markup Language)/XML (eXtensible Markup Language). Version 2002 of the EAD DTD was finalized in December 2002. It supersedes version 1.0, released in August 1998. It also contains links to related files. The 2002 version is the second production release of the EAD DTD. It incorporates a small number of newly-defined elements, deprecates eight previously used elements, and modifies the structure (content model) for a few elements to allow the inclusion of other valid EAD elements at different levels within a finding aid.

This paper is designed to introduce the reader to the grammar used in XML DTDs to declare elements and attributes. It does not rigorously define this grammar, nor does it define the entire grammar used in DTDs. Among other things, the grammar for notations and entities is omitted. For a complete definition of the DTD grammar, see the XML specification or the annotated XML specification.

The version of the DTD available from this page will be updated gradually to incorporate any corrections or changes since the MathML2 Recommendation.

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to OASIS, except as needed for the purpose of developing OASIS specifications, in which case the procedures for copyrights defined in the OASIS Intellectual Property Rights document must be followed, or as required to translate it into languages other than English.

The National Center for Biotechnology Information (NCBI), a center of the National Library of Medicine (NLM), created the Journal Publishing Document Type Definition (DTD) with the intent of providing a common format for the creation of journal content in XML.

Many documents on the Web use non-standard elements such as EMBED and non-standard attributes such as the LEFTMARGIN attribute on the BODY element. These documents will not validate against standards like HTML 3.2 or HTML 4.0, but validation is too important a tool to be ignored for this reason.

List of valid DTDs you can use in your document.

List of J2EE DTDs

The purpose of a Document Type Definition is to define the legal building blocks of an XML document. It defines the document structure with a list of legal elements.

DTD parsers for Java seem to be pretty scarce. That's probably because DTD isn't valid XML. At some point, if/when XML Schema becomes widely accepted, no one will need DTD parsers anymore. Until then, you can use this library to parse a DTD.

This report describes the XML specification ("XMLspec") DTD used for World Wide Web Consortium (W3C) specifications and notes related to XML. It is maintained by Eve Maler (, +1 781 442 3190) of Sun Microsystems. This release of the report corresponds to the DTD with the formal public identifier "-//W3C//DTD Specification Version 2.1//EN".

The National Center for Biotechnology Information (NCBI) of the National Library of Medicine (NLM) created the Journal Archiving and Interchange Document Type Definition (DTD) with the intent of providing a common format in which publishers and archives can exchange journal content.