This isn’t brand-new news, but I’m finding that a lot of people haven’t heard about it, and it’s useful. From GoogleBlog:
Follow the link if you want more technical info. Here and now, a simplified version: Google’s implemented a tag you can tuck into the code you use to make a link. It looks like this. Here’s a standard link:
Preventing comment spam
If you’re a blogger (or a blog reader), you’re painfully familiar with people who try to raise their own websites’ search engine rankings by submitting linked blog comments like “Visit my discount pharmaceuticals site.” This is called comment spam, we don’t like it either, and we’ve been testing a new tag that blocks it. From now on, when Google sees the attribute (rel=”nofollow”) on hyperlinks, those links won’t get any credit when we rank websites in our search results. This isn’t a negative vote for the site where the comment was posted; it’s just a way to make sure that spammers get no benefit from abusing public areas like blog comments, trackbacks, and referrer lists.We hope the web software community will quickly adopt this attribute and we’re pleased that a number of blog software makers have already signed on…
<a href=”http://www.jesshutch.com/robotmain.html”>Link.</a>And here’s one with Google’s new tag:
<a href=”http://www.jesshutch.com/robotmain.html” rel=”nofollow”>Link.</a>Any link with the “nofollow” tag in it won’t count toward the linked-to site’s popularity in the Google ratings, a.k.a. its Googlejuice. This does away with the chief benefit (to the spammers) of posting comment spam.
As I understand it, it’s possible to set things up so that links posted into comment threads, guestbooks, trackbacks, and referrer lists will have the “nofollow” tag automatically added to their code. Commenters will still be able to post links there, but there’ll be no incentive to post commercial links en masse.
Meanwhile, the tag can also be used to avoid upping the traffic (and thus the Google ratings) of objectionable sites one may have occasion to link to. For instance, Warren Whitlock: he’s getting no Google hits from Making Light.
It’s a good thing.