February 15, 2009
Google Yahoo and Microsoft Agree on Canonical Link Element
Arguably the most important SEO initiative announced at SMX West last week came from Google’s chief quality czar, Matt Cutts, who outlined a new Canonical link element which will tell search engines which version of a page a webmaster wants indexed. Designed to delete duplicate content from the search engine indexes, the new relational element allows search spiders to determine which pages to index and which pages to gloss over without adding duplications of pages to their indexes. The element has been accepted by the three major search engines, each of which has pledged support for it. For example, image a content management system that automatically names pages with numbers or appends tracking or session IDs to a URL string. A URL leading to a page about something nice like Rupert the Bear might read: http://www.yoursite.com/specific-page.html?sid=yucky85448633572/. A good SEO would rather that URL be phrased in a far cleaner and clearer way: http://www.yoursite.com/rupert-bear.html/. The element looks like this; <link rel=”canonical” value="http://www.YOURSITE.com/correct-page.html"/>, and is coded in place of the 301 redirect formerly used to steer spiders to the correct version of a specific page. Google, Yahoo! and Microsoft have all published information on how to implement the relational link element in the HEAD section of your website. A note of caution; the Canonical link element is domain specific and will not pass juice between different domains though it will within a sub-domain structure. Also, Joost de Valk (happy birthday Joost) has written several WordPress, Magento and Drupal plug-ins for the Canonical link element.