Also from: CONTENTS
The Contents variable inserts a table of contents on the page. Note that a table of contents may automatically be generated, even if this variable is not used.
The Contents variable is usually placed somewhere near the top of the page, as it is most useful there to allow users to go directly to headings on the page below.
A table of contents presents users with links to each of the headings on the page. They are most useful on pages that don't fit in their entireity on the screen, as they allow quick navigation of a page.
In most cases, this variable will not be required as a table of contents is automatically generated when appropriate. If there are three or more headings on a page, a table of contents is placed in the top right corner of the page.
Level 1 headings (which are only used for the first page heading) are not included in a table of contents, although all other headings are.