Posts Tagged microsoft
Canonical URL Links / Tags
Posted by Chris in Search Engine Optimisation on March 25th, 2009
I have just been reading up on this new canonical link tag that the three top search engines have started implementing. Google, Yahoo and Microsoft have just announced a new tag, which we can use to tell the search engines which URL it should have for the current page. – yoast.com
In short, this is a way for SEO’s to help prevent duplicate content from being cached in search engines. This tag can be used on pages where there is duplicate information on a number of pages and points the search engines to the page that you would prefer to have cached. A good example is were you may have a page with variables in the URL like session keys or variables used to sort data. The same content will appear on many pages, but you don’t want duplicate content penalties. Even example.com and www.example.com, which point to the same page (normally), will show up as duplicate content.
Sample URL that may have duplicate content:
http://www.pagestrength.com/2009/03/canonical-url-links-tags/?source=firefox-search
Example canonical code that should be placed in the <head> tags:
<link rel="canonical" href="http://www.pagestrength.com/2009/03/canonical-url-links-tags/" />
I intend to try it out on my referral system in my directories, so that any referrals that use ?ref=123 in the URL can rather “hint” to the search engines that I would prefer to use the home page… hmmm, I wonder if this will pass on PageRank at all. I hope so! I will test it and let you know… may take a few months I would say. 
Matt Cutts explains it well, see below…
