Possible Values
Alternate a substitute file
Appendix an appendix page
Bookmark,
Chapter, a chapter page
Contents the table of contents
Copyright,
Glossary,
Help,
Index the index page
Next the next page
Prev the previous page
Section a page that is a section of a group of pages
Shortcut Icon the href to an icon
Start the first page
Stylesheet,
Subsection a subsection page