The Googlebot!
Creative Commons License photo credit: cote

The rel=”nofollow” attribute on links is very usefull.  Additionally nofollow in robots can be usefull.  They should not be confused with eachother.

The rel=”nofollow” description below is courtesy of robotstxt.org :)

The rel=”nofollow” is an attribute you can set on an HTML <a> link tag, invented by Google, and adopted by others. Those links won’t get any credit when Google ranks websites in the search results, thus removing the main incentive behind blog comment spammers robots.

See Preventing comment spam on the Official Google Blog.

From that description it sounds like it only affects the ranking, and the Google robot may still follow the links and index them. If so, it is different from the robots meta tag NOFOLLOW semantics.

Additionally, the below is courtesy of robotstxt.org too :) 

<html>
<head>
<title>...</title>
<META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">
</head>

There are two important considerations when using the robots <META> tag:

  • robots can ignore your <META> tag. Especially malware robots that scan the web for security vulnerabilities, and email address harvesters used by spammers will pay no attention.
  • the NOFOLLOW directive only applies to links on this page. It’s entirely likely that a robot might find the same links on some other page without a NOFOLLOW (perhaps on some other site), and so still arrives at your undesired page.

Now, get using nofollow links! :P