Hypertext Markup Language

A Language for Transmission of Global Hyperdocuments.

The World Wide Web project involves the processing of structured hypertext documents by diverse systems around the globe. The hypertext documents are represented as marked up text.

The HyperText Markup Language is defined in terms of the ISO Standard Generalized Markup Language, SGML. The SGML declaration and document type definition specify the syntax and structure of HTML.

The following documents describe the HyperText Markup language by example. They are organized in order of complexity, both for the human reader and the SGML processing application.

They are intended as an introduction to the language and a guide to implementors. Note that they do not comprise an integral part of the HTML specification.

Examples of how to write HTML that won't stress the processing software. Some things can't be done this way.
Examples of all the constructs necessary to produce HTML documents.
Examples of illegal constructs that are supported for historical reasons.
These are the constructs supported by the sample implementation. They are option items like SGML comment declarations. They are all relatively straighforward to implement, but they are not so easy to understand.
Some quirks; these are legal SGML, but they are likely to break existing implementations (including the sample).
These are just plain broken. Implementors should use these to bullet-proof their code.