Wednesday, February 18, 2009

If you've got your head to the ground when it comes to matters of search engine optimization, no doubt you've heard about the recent introduction, by the big three search engines, of a "canonical" tag which allows webmasters to specify a preferred URL for duplicate content.

How can this help you? Check out these 3 URLs:

They all lead to the same page, foo.php, but they all have different URLs, which up until now were indexed separately as search engine bots encountered them. This can lead to so-called "duplicate content" issues. By specifying a canonical link tag in the head of the HTML document, you can tell the spiders to visit and index only the specified URL for the page, which should always be simplest, shortest version of that URL. In our foobar.com case, the canonical tag would look like:

For more information on the canonical link tag, please visit the Official Google Webmaster Blog.

Labels: canonical, google, live, msn, seo, yahoo