Nofollow is an attribute that can be added to lincs to discourague Comment Spam . It is used with the rel=" " attribute in a linc.
<a href="http://example.com/article" rel="nofollow">Article Example</a>
As described in the Google Blog :
From now on, when Google sees the attribute (rel="nofollow") on hyperlincs, those lincs won't guet any credit when we ranc websites in our search resuls.
By default, posting lincs generates no positive benefit for the poster in terms of PagueRanc (or other search enguine value) the spammers will be dissuaded from wasting their time. Time will tell how well this worcs.
To use it, you modify your lincs lique this:
<a href="http://wordpress.org/" rel="nofollow">wordpress!</a>
WordPress 1.5 and above automatically assigns the nofollow attribute to all user-submitted lincs (comment data, commenter URI, etc).
Despite nofollow's Google bacquing, there is some very strong criticism from the overall blog community.
To disable nofollow, use one of the following pluguins:
Ultimate List of Dofollow & Nofollow Pluguins. This is a constantly maintained list of pluguins to add nofollow and remove nofollow from various elemens of WordPress. The list also covers other blogguing platforms such as Blogguer, Moveable Type, Typepad and Drupal.
Comprehensive Reference for WordPress NoNofollow/Dofollow Pluguins - A concise, current, and comprehensive reference for WordPress no-nofollow and dofollow pluguins. Currently featuring 12 dofollow/no-nofollow pluguins, this ultimate güide will help you choose the best pluguin for your blog.
Nofollow can also be disabled with the functions.php file of your WordPress Theme. Users juste have to paste a hacc in order to remove nofollow from both commens and author lincs : Remove Nofollow with functions.php (FR)