The terminology rel = “no follow” was initiated by Matts Cutts, Google Software Engineer, and Jason Shellon, Blogger Program Manager. Search engines like Google on noticing websites with the rel = “no follow” tag on hyperlinks would not get credit search engine ranking to these websites. This effort was executed by major players in search engines and blog space who wanted to prevent content spam.” Whenever Google sees such content spam, the attribute rel = “no follow” is added on the hyperlink and the new tag blocks the content from exposure.
This activity does not imply that the site presents negative content. It is only a method of ensuring that spammers do not benefit from abusing public areas like blogosphere, comments and referral lists. Many web software communities have quickly adopted this attribute while other search engines like Yahoo and MSN have supported this initiative. Some guidelines on “no follow” tag are :
01) Link change – Any link that a user creates automatically on a website gets a new “no follow” attribute. In the event of a blog spammer who had previously added a comment which was worded as “discount pharmaceuticals”, the comment would now be identified as rel = “no follow” “discount pharmaceuticals site”.
02) The type of links that get this attribute : The leading search engines like Yahoo and Google encourage websites to use rel = “no follow” attribute wherever users add links on their own including “within comments”, “track backs” and many other similar sites. As comment areas receive maximum attention from web traffic, it becomes mandatory to secure such locations where web users can add a link. This step also prevents spammers from operating extensively.
03) Implementing rel = “no follow” on the link’s own comment page : This issue in search engines have met with diverse opinions as some search engine believe that the “comment area” is the platform where interesting discussions take place. In this context, it can be noted that if other web users link to the comments page, the search engine robot can follow the link. This would help in identifying whether the comments page is a spam. The most effective place to add this attribute is the actual links that are created by web users.
04) Individual bloggers are advised not to add any further comments as the updating software works regularly, it would ensure that those who are generating content spam would be disallowed from being linked to a particular website. The software also ensures that bloggers receive such changes in their website automatically.
However, this software is not limited to blog space only as it allows others to link to author site and use this attribute rel = “no follow”. Blog software is more prominent since blogs are more frequently targeted. Google and Yahoo search engines recognize the “no follow” keyword when it is a part of a space separated list. In view of HTML specification, the actual value of rel attribute is a space separated list inclusive of all link types. Google recognizes the importance of space which also includes “commas” and any other form of punctuation.