Use headings to structure your document
Structure your document
Most pages (especially text, but also graphics and multimedia) have structure that the author uses to make the content clearer. In (X)HTML it is possible to use heading elements of various levels to provide some of that structure.
This can be used by people as a table of contents (many tools generate a table of contents like this), or to break the page into smaller chunks, for example to send to a small device. it can also be used to determine the key concepts in a page (as some search engines do).
The Markup validator will provide an outline view of an (X)HTML page to show the structure - this is usually presented with distinctive text styling, although the details of your presentation can be set using a style sheet. If your page has several regular text styles but no heading elements, it may be that those really are headings, but are only being marked as paragraphs with a different style.
Headings tags
All the various flavors of (X)HTML define 6 levels of headings: <h1>, <h2>, <h3>, <h4>, <h5>, <h6>. It is foreseen that XHTML 2 will also provide generic headings, with a level determined by their depth in the structure.
Further Reading
- Headings in HTML 4.01
- Outline of the document generated by the Markup Validator
- an HTML Semantics extractor
About the "QA Tips"
The W3C QA Tips are short documents explaining useful bits of knowledge for Web developers or designers, hosted and produced by the Quality Assurance Interest Group at W3C.
While the tips are carefully reviewed by the participants of the group, they should not be seen as anything else than informative bits of wisdom, and especially, they are not normative W3C technical specifications.
Learn more about the Tips, how to submit your own pearls of wisdom, and find all the other QA tips in the Tips Index.