2.1 Levels of Conformance

Version 2.0 of the HTML specification introduces forms for user input of information, and adds a distinction between levels of conformance:

Level 0

Indicates the minimum conformance level. When writing Level 0 documents, authors can be confident that the rendering at different sites will reflect their intent.

Level 1

Includes Level 0 features plus features such as highlighting and images.

Level 2

Includes all Level 0 and Level 1 features, plus forms. Features of higher levels, such as tables, figures, and mathematical formulae, are under discussion and are described as proposed where mentioned.