Duplicate Content Issues
The issue websites have is duplicate content, the same content is indexed under different URL’s. This is an issue SEO’s have been trying to solve for a long time.
New canonical URL tag
To help solve this problem, the 3 major engines have declared that it will recognise a new HTML tag, which, if inserted into your web page, will allow you to specify which URL you want to be the “official”, URL for the content.
The tag needs to be inserted into the
HEAD section of your web page:
<link rel="canonical" href="http://www.yourwebsite.co.uk/correct-page.html">
<link rel="canonical" href="http://www.yourwebsite.co.uk/correct-page.html" />
This code needs to be placed in the
HEAD section not in the
Google will now count the links it has seen to that campaign tagged URL, towards the canonical URL, and not index the campaign tagged URL.
In summary, may be to early to tell if this will help webmasters as it was only announced on the 12th February 2009, but in my opinion this is handing back a little bit of control to the webmaster instead of letting the search engine’s figure out the correct URL.
Disclaimer: The tag is aonly a suggestion to the search engine. It will probably be used 99% of the time, but they have the right to handle things their way.
Canonical URL plugin for WordPress users now available from Joost de Valk.