No, this is not a post about Twitter, but a neat little tag, that can be used in numerous ways both to preserve link juice, and as a hindrance to your SEO efforts.

The No-follow tag is a simple piece of code that can be added to links on a website to tell Googlebot not to follow a link, and thus preserve some of the page rank of your site to its most important pages. Examples of when you would use this is in the case of non-important pages content wise, such as contact us, privacy, terms and conditions etc.

it appears under the code rel-nofollow so if you had  link that you thought would be intersting to your customers but you really didn’t want Google to give away all you hard earned link juice you would enter the following <a rel="nofollow" href="http://www.example.com/">Anchor Text</a>

In 2008, Matt Cutts, Google’s software engineer posted the following

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.

However be very careful when obtaining links back to your site, that you make sure that this tag isn’t added, otherwise you could be wasting your time placing a link on that sit, as it would add no link juice or have any effect to your rankings.

To find out whether a site has no follow tag’s, there is an excellent firefox plugin called NoFollow. Any links on a site that have the nofollow tag are highlighted in red, whilst dofollow are in grey.

I use this tool all the time, and find a great timesaver.