Sunday, October 28, 2007

Nofollow Tag

Nofollow is a non-standard HTML attribute value used to instruct search engines that a hyperlink should not influence the link target's ranking in the search engine's index. It is intended to reduce the effectiveness of certain types of spamdexing, thereby improving the quality of search engine results and preventing spamdexing from occurring in the first place.

While all engines that support the attribute exclude links that use the attribute from their ranking calculation, the details about the exact interpretation of the attribute vary from search engine to search engine.

* Google takes "nofollow" literally and does not "follow" the link at all. That is supposedly their official statement, but experiments conducted by SEOs show conflicting results. They show instead that Google does follow the link, but not index the linked-to page, unless it was in Google's index already for other reasons (such as other, non-nofollow links that point to the page). Links with NOFOLLOW are included in the back-links reporting data at Google's Webmaster Central.
* Yahoo! "follows it", but excludes it from their ranking calculation.
* MSN Search respects "nofollow" as regards not counting the link in their ranking, but it is not proven whether or not MSN follows the link.
* does not use the attribute for anything.

From Wikipedia, the free encyclopedia