XML - Document Type (Definition|Declaration) (DTD)

Card Puncher Data Processing


Document Type Definition (DTD) is a grammar (language) that defines the schema (ie data structure) of an XML document.



The syntax is a set of markup declarations that define a document type for SGML-family markup languages (SGML, XML, HTML).

DTDs were a precursor to XML schemas and have a similar function, although different capabilities.

A DTD can be declared:

  • inline inside an XML document,
  • or as an external reference.

The document type declaration can point to an external subset (a special kind of external entity) containing:

  • markup declarations,
  • or can contain the markup declarations directly in an internal subset,
  • or can do both.

The DTD for a document consists of both subsets taken together.

DTD are context-free grammars

Documentation / Reference

Discover More
Card Puncher Data Processing
Extensible Markup Language (XML)

is a flexible way to create common information formats and to share the formats and data between applications and on the internet. XML is, essentially, a platform-independent means of structuring informationelementschemjsoXML...
HTML - (Specification | API | Standard )

In HTML, there is two specifications: the - how to write an HTML document the API (dom) - how to build a DOM document from a HTML document and manipulate it The syntax is specified in the the...

The DTD of HTML can be found in the specification documents. It defines the schema of a valid HTML page. For instance html401
How is the DOM document build from an HTML document ?

This page is about the construction of the DOM document from a HTML document (ie the XML language is xhtml) HTMLAPIHTML The HTML dom document is created: * by an xml library * or by the browser...
Language - Context Free Grammar (CFG)

A context-free grammar is: a set of instructions called grammar rules (known as production rules or production) that describe all possible strings in a given formal language without context ...
Multilingual Regular Expression Syntax (Pattern)

Regular expression are Expression that defines a pattern in text. This is therefore a language that permits to define structure of a text. They are a mathematically-defined concept, invented by Stephen...
Card Puncher Data Processing
XML - (Markup) Declaration (validation|constraint)

The element structure of an XML document may, for validation purposes, be constrained using: element type and declarations defined in the doctype: inlined or externally via dtd file These...
Card Puncher Data Processing
XML - (Structured) Document

Documents are built from node (elements and text node between node element). These elements form a tree using the DOM. Each XML documents begin with an XML declaration which specifies the version of...
Card Puncher Data Processing
XML - (Structure|Representation)

Each XML document has both: a and a structure. XML provides a mechanism, the document type declaration: to define constraints on the logical structure and to support the use of predefined...
Card Puncher Data Processing
XML - (XML Schema Definition|XSD) (Schema With Capital S)

The in XML. XML Schema definition language (Xsd) is a language that define an XML schema (usually written in the W3C XML Schema Language). It provides functionality...

Share this page:
Follow us:
Task Runner