Google Search Engine Optimisation Starter Guide - Manual (Page 19)

Google's Search Engine Optimisation Starter Guide, Version 1.1, 13 Nov 2008, latest version at Google Webmaster Central
A comment spammer leaves a message on one of our news posts, hoping to get some of our
site's reputation
Another use of nofollow is when you're writing content and wish to reference a website, but don't want to
pass your reputation on to it. For example, imagine that you're writing a blog post on the topic of
comment spamming and you want to call out a site that recently comment-spammed your blog. You
want to warn others of the site, so you include the link to it in your content; however, you certainly don't
want to give the site some of your reputation from your link. This would be a good time to use nofollow.
Lastly, if you're interested in nofollowing all of the links on a page, you can use "nofollow" in your robots
meta tag, which is placed inside the tag of that page's HTML. The Webmaster Central Blog
provides a helpful post on
using the robots meta tag . This method is written as
content="nofollow">.
This nofollows all of the links on a page