rel-license

rel="license"

Rel-License is a simple, open, format for indicating content licenses which is embedable in HTML or XHTML, Atom, RSS, and arbitrary XML. Rel-License is one of several microformat open standards.

Specification 2005-02-06

Author

Tantek Çelik (Technorati, Inc., formerly of Microsoft Corporation)

Copyright

Per the public domain release on my user page, this specification is released into the public domain.

Public Domain Contribution Requirement. Since the author(s) released this work into the public domain, in order to maintain this work's public domain status, all contributors to this page agree to release their contributions to this page to the public domain as well. Contributors may indicate their agreement by adding the public domain release template to their user page per the Voluntary Public Domain Declarations instructions. Unreleased contributions may be reverted/removed.

Patents

This specification is subject to a royalty free patent policy, e.g. per the W3C Patent Policy, and IETF RFC3667 & RFC3668.

Abstract

Rel-License is one of several microformats. By adding rel="license" to a hyperlink, a page indicates that the destination of that hyperlink is a license for the current page. E.g. with the following hyperlink:

<a href="http://creativecommons.org/licenses/by/2.0/" rel="license">cc by 2.0</a>

the author indicates that the page is licensed under a Creative Commons 2.0 Attribution Required license.

Multiple Licenses

Multiple such rel="license" hyperlinks indicate that the page is available under any of the referred licenses. E.g. the following hyperlinks could be used to declare that a page is available under either a Creative Commons 2.0 Attribution Required license or the Apache 2.0 license:

<a href="http://creativecommons.org/licenses/by/2.0/" rel="license">cc by 2.0</a>
<a href="http://www.apache.org/licenses/LICENSE-2.0" rel="license">Apache 2.0</a>

XMDP profile

<dl class="profile">
 <dt id="rel">rel</dt>
 <dd><p>
   <a rel="help" href="http://www.w3.org/TR/html401/struct/links.html#adef-rel">
     HTML4 definition of the 'rel' attribute.</a>  
   Here is an additional value.</p>
  <dl>
   <dt id="license">license</dt>
   <dd>Indicates that the referred resource is a license for the referring page.</dd>
  </dl>
 </dd>
</dl>

Implementations

• Dreamweaver Extension suite from the Web Standards Project enables the authoring of rel-license links from within Dreamweaver 8. Includes (cc) defaults.
• pnh_mf is a plugin for Textpattern that supports embedding rel license and other microformats in templates and blog posts. Written by Chris Casciano.
• Creative Commons (cc) license chooser
• Yahoo! (cc) search (appears to pick up link-rel in a but not link elements)
• Google "Usage Rights" search (also appears to pick up link-rel in a but not link elements)

List of Licenses

CC

References

Normative References

• XMDP

Informative References

• 20040211 rel="license" first proposed in presentation real world semantics at 2004 O'Reilly Emerging Technologies Conference, San Diego, CA, USA.
• 20040225 Thorough discussion of rel="license" including advantages and presentation possibilities.
• Creative Commons 2.0 By (Attribution Required) license
• Apache 2.0 license
• Contributed from http://developers.technorati.com/wiki/RelLicense
• Know your rel-license at Microformatique

see also

• rel-license-issues - issues which have been raised with this microformat.
• rel-faq