The table of contents serves two purposes:

• It gives users an overview of the document's contents and organization; and

• it allows readers to go directly to a specific section of an online document .

The table of contents typically includes only major sections of the document, though in some cases an expanded table of contents that provides a more detailed view of a complex document may be desirable.

The table of contents should provide links to section headings and sub-headings within the hierarchical structure of the document. Authoring tools or user agents may create tables of contents automatically, based on section headings in the document. Authors or users may be able to control how much of the document structure is displayed in the table of contents.

The table of contents may include many links and may extend over several screens. It may add significantly to the actual and perceived length of the document. This can create difficulties for people using screen readers and screen magnifiers as well as for people who use a keyboard or keyboard interface. Therefore, it is good practice to allow users to skip over the table of contents. This can be accomplished by using a section heading to mark where the Table of Contents begins and by providing a link that bypasses it. In some cases it may be helpful to place the Table of Contents in a separate document.