New link relations in HTML5

Several new rel attributes for the <a> and <link> elements have been proposed for HTML5. Existing attributes from HTML4 may be redefined somewhat. They include:

• <rel='alternate'>

  • may be used with link, a, and area elements
  • meaning depends on the values of the other attributes such as 'stylesheet' or 'type'

• <rel='icon'>

  • may be used with link elements
  • specified resource is an icon representing the page or site

• <rel='nofollow'>

  • may be used with a and area elements
  • the link is not endorsed by the original author or publisher of the page

• <rel='prefetch'>

  • may be used with link elements
  • preemptively fetches and caches the specified resource

• <rel='archives'>

  • may be used with link, a, and area elements
  • indicates that the referenced document describes a collection of records, documents, or other materials of historical interest.

• <rel='external'>

  • may be used with a and area elements
  • indicates that the link is leading to a document that is not part of the current site

• <rel='license'>

  • may be used with link, a, and area elements
  • the referenced document provides the copyright license terms

• <rel='noreferrer'>

  • may be used with link, a, and area elements
  • user agent must not include a Referrer HTTP header  in the request

• <rel='pingback'>

  • may be used with link elements
  • usage is still being defined, but it creates a hyperlink

• <rel='sidebar'>

  • may be used with link, a, and area elements
  • the referenced document, if retrieved, is intended to be shown in a secondary browsing context (if possible). It isn’t clear if this means a new tab, a new window, or an iFrame.

• <rel='tag'>

  • may be used with link, a, and area elements
  • the tag that the referenced document represents applies to the current document

The best I can tell from looking at the current specs, these relative types of links are current in the HTML5 proposal. I hope I haven’t missed any.