Nofollow
Also called: rel="nofollow"
By assigning hyperlinks an html attribute rel="nofollow," search engines are asked not to include the link in their algorithms for ranking search results, such as PageRank.
Search engines use links on the Web to discover new pages and determine the authority of those links. They see the posting of a link as a signal that the linked page is worthwhile.
When there is a financial quid pro quo, such as posting a text link for a fee, it can be seen as an attempt to manipulate search results. Search engine webmaster guidelines therefore call on webmasters to add the attribute rel="nofollow" to paid links so that paid links can be easily ignored.
When paid links are still placed without nofollow, both the linked site and the site where the link is located risk a penalty.
By SEO professionals, the nofollow is sometimes jokingly called link condom.
