This page lists the allowed extension values for the rel="" attribute in HTML5. You may add your own values to this list, which makes them legal HTML5 rel values. We ask that you try to avoid redundancy; if someone has already defined a value that does roughly what you want, please reuse it.
|Keyword||Effect on...||Brief description||Link to more details||Synonyms||Status|
|link||a and area|
|script||not allowed||not allowed||Was proposed to replace <script>. Use <script> instead.||none||Rejected|
|glossary||Hyperlink||Hyperlink||Target document provides definitions for words in current document.||HTML4||Proposal|
|chapter||Hyperlink||Hyperlink||Target document is a subdocument of the current document.||HTML4||section, subsection, appendix||Proposal|
The "Allowed on... link" column must either say "not allowed", if the rel value is not allowed on <link> elements, or "hyperlink", if the rel value creates a hyperlink, or "external resource", if the rel value creates a link to an external resource.
The "Allowed on... a and area" column must either say "not allowed" or "hyperlink".
For the "Status" section to be changed to "Accepted", the proposed keyword must have been through the Microformats process, and been approved by the Microformats community.
For more details, see the HTML5 specification.