Introduction

The HyperText Markup Language (HTML) is a simple data format used to create hypertext documents that are portable from one platform to another. HTML documents are SGML documents with generic semantics that are appropriate for representing information from a wide range of domains.

Scope

HTML has been in use by the World-Wide Web (WWW) global information initiative since 1990. This specification corresponds to the capabilities of HTML in common use prior to June 1994 and referred to as "HTML 2.0".

HTML is an application of ISO Standard 8879:1986 Information Processing Text and Office Systems; Standard Generalized Markup Language (SGML). The HTML Document Type Definition (DTD) is a formal definition of the HTML syntax in terms of SGML.

This specification also defines HTML as an Internet Media Type[IMEDIA] and MIME Content Type[MIME] called `text/html', or `text/html; version=2.0'. As such, it defines the semantics of the HTML syntax and how that syntax should be interpreted by user agents.

Conformance

This specification governs the syntax of HTML documents and the behaviour of HTML user agents.

Documents

A document is a conforming HTML document only if:

• It is a conforming SGML document.
• It conforms to the application conventions in this specification. For example, the value of the `HREF' attribute of the `A' element must conform to the URI syntax.

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The HTML DTD defines a standard HTML document type and several variations, based on feature test entities:

HTML.Recommended

Certain features of the language are necessary for compatibility with widespread usage, but they may compromise the structural integrity of a document. This feature test entity enables a more prescriptive document type definition that eliminates those features. For example, in order to preserve the structure of a document, an editing user agent may translate HTML documents to the recommended subset, or it may require that the documents be in the recommended subset for import.

HTML.Deprecated

Certain features of the language are necessary for compatibility with earlier versions of the specification, but they tend to be used an implemented inconsistently, and their use is deprecated. This feature test entity enables a document type definition that eliminates these features. Documents generated by tranlation software or editing software should not contain these idioms.

User Agents

An HTML user agent conforms to this specification if:

• It parses the characters of an HTML document into data characters and markup as per [SGML].
• It behaves identically for documents whose parsed token sequences are identical. For example, comments and the whitespace in tags disappear during tokenization, and hence they do not influence the behaviour of conforming user agents.
• It allows the user to traverse (or at least attempt to traverse, resources permitting) all hyperlinks in an HTML document.
• It allows the user to express all form field values specified in an HTML document and to (attempt to) submit the values as requests to information services.

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