Link Specific Regulation: REL=NOFOLLOW

Hindring search engines to interpret a link as a vote for the link target

Steering SE Crawlers · Index · Expand · Web Feed

URL Specific Control: the Robots META Tag

Tagging irrelevant page areas: class=robots-nocontent

Google has introduced the NOFOLLOW value in the <A> tag's REL attribute in January, 2005, as an instrument to prevent comment spam. Yahoo, MSN and guestbook/forum/blog software makers quickly joined the initiative. In the meantime this syntax found its way into Google's guidelines and Google reps encourage webmasters to use it anytime they can't vouch for a link.

If you can't vouch for a link, for example because it's added by a user or scraped from a foreign source, add REL=NOFOLLOW to the link. If you want to make other use of the REL attribute, separate the values by spaces. Example links:

<A HREF='http://foreignDomain.com/anyPage.html' REL='NOFOLLOW'>anchor text</A>
<A HREF='http://foreignDomain.com/anyPage.html' REL='external nofollow'>anchor text</A>

This is not a negative vote for the page you link to. Use REL=NOFOLLOW carefully and don't abuse it. Links marked with REL=NOFOLLOW do not pass PageRank™ to the linked page, that means they do not contribute to the link popularity of the target. There are good reasons not to use REL=NOFOLLOW to hoard PageRank™. First, PageRank™ hoarding is easy to discover and you will earn a ranking penalty for over-optimizing. Second, other webmasters are smart too and will cancel link trades if you cheat.

Search engine crawlers harvest even unlinked URLs. In rare cases when it's necessary to hide a URL from spiders completely, don't output it server sided. Use java script to write the URL string in the web browser then.

Tagging irrelevant page areas: class=robots-nocontent

URL Specific Control: the Robots META Tag

Steering and Supporting Search Engine Crawling · Index · Part 1 · 2 · 3 · 4 · 5 · 6 · 7 · 8 · 9 · 10 · Expand · Web Feed