rel-nofollow

rel="nofollow"

Draft Specification 2005-01-10

Editors

• Tantek Çelik, Technorati, Inc.
• Kevin Marks, Technorati, Inc.

Concept

• Matt Cutts, Google, Inc
• Jason Shellen, Blogger/Google

Copyright

This specification is (C) 2005-2024 by the authors. However, the authors intend to submit (or already have submitted, see details in the spec) this specification to a standards body with a liberal copyright/licensing policy such as the GMPG, IETF, and/or W3C. Anyone wishing to contribute should read their copyright principles, policies and licenses (e.g. the GMPG Principles) and agree to them, including licensing of all contributions under all required licenses (e.g. CC-by 1.0 and later), before contributing.

Patents

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

Abstract

RelNoFollow is one of several MicroFormats. By adding {{{rel="nofollow"}}} to a hyperlink, a page indicates that the destination of that hyperlink SHOULD NOT be afforded any additional weight or ranking by user agents which perform link analysis upon web pages (e.g. search engines). Typical use cases include links created by 3rd party commenters on blogs, or links the author wishes to point to, but avoid endorsing. For more specific endorsement (or lack thereof) semantics, see VoteLinks.

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="nofollow">nofollow</dt>
   <dd>Indicates that the referred resource was not necessarily linked to 
       by the author of the page, and thus said reference should not afford 
       the referred resource any additional weight or ranking by user agents. </dd>
  </dl>
 </dd>
</dl>

normative references

• XMDP
• http://www.google.com/googleblog/2005/01/preventing-comment-spam.html

informative references

• VoteLinks can be used by an author to explicitly state their support for or against, or neutrality toward the destination of a link. Implementers implementing rel="nofollow" and VoteLinks should similarly not afford any additional weight or ranking to links with either {{{rel="vote-abstain"}}} or rel="vote-against".

open issues

These are open issues that have been raised about rel="nofollow" that have been raised in various forums, in particular, on the public W3C www-html mailing list. They have been grouped into four areas.

• Definition. nofollow indicates a behavior rather than a relationship from which the behavior should be inferred as appropriate for the useragent. rel values should be nouns that indicates what the resource being referenced is in relation to the source.
• Name. nofollow is a bad name.
  • overloading. does not mean the same as robots exclusion standards (robots.txt, meta robots) nofollow.
  • does not mean what it says. does not mean "do not follow this link", rather it means " do not add weight from this link". Asbjørn Ulsberg
  • not a noun. see above.
  • suggested alternatives:
    • noendorse - Micah Dubinko
    • none
    • noweight
    • unendorsed - Lachlan Hunt
    • unrelated - Jens Meiert
    • untrusted
• Efficacy. nofollow will not affect spamming behavior.
• Collateral Damage. If tools automatically add nofollow to all 3rd party links, then many legitimate non-spam links will be ignored or given reduced weight, and thus the destination of such links will be unfortunate casualties.