rel=”nofollow”, is said to be the next biggest thing to be used by shady webmasters engaging in reciprocal link exchanges. This attribute was introduced by Google as a means to prevent the problem of comment spamming in weblogs, also called “Blogs”, and it looks to be adopted by all other major search engines such as Yahoo! and MSN.

“rel” is an attribute, not a tag

rel=”nofollow” has been inaccurately called a HTML tag. It is in fact an attribute that can be added to HTML tags, similar to adding the attribute “width” to HTML tags such as <IMG> or <TABLE>. The attribute rel=”nofollow” is used on individual anchor tags <A> for links.

Purpose of rel=”nofollow”

Any link with this attribute will indicate to search engine robots that the landing page may not be approved by the web site listing this link and therefore the link will not contribute to the link popularity or ranking of the landing page.

Example link using rel=”nofollow”

An example of the use of this attribute in a link is displayed below. The resulting link, while still visible to visitors, will not contribute to Google’s link popularity, PageRank or search engine ranking (not that they really need any).

Impact on link exchanges

While this attribute is clearly beneficial, especially for preventing spammers from abusing Blogs, guestbooks and other public areas where comments can be submitted, one of the concerning consequences is shady webmasters using it for the links on their links pages and directories. A link using the attribute rel=”nofollow” is not completely worthless, visitors can still come to your web site through this link, however you will be losing out when it comes to link popularity and search engine rankings.

Another possible abuse of rel=nofollow is the use of this attribute applied to the link pointing to the links page or directory. By applying rel=nofollow in this way, the outgoing links on the links page appears valid, however, because the links page is not “approved” by the page linking to it, the links page will not receive PageRank or link popularity. Hence a link on such a page would not pass on any benefits in terms of link popularity and search engine rankings.

More information

Looking for the source of this article? Read Google’s Blog on Preventing Comment Spam. You may also be interested in what MSN and Yahoo! has to say about this new attribute.

Learn how to detect rel=”nofollow” for Safari on Mac OS X using a javascript bookmark. You can also detect rel=”nofollow” on Firefox for Windows, Linux and Mac OS X.