Canonical Tag for SEO

Last week Google, Yahoo, and Microsoft announced support for a new link element to clean up duplicate urls on sites. The syntax is pretty simple: An ugly url such as http://www.example.com/page.html?sid=asdf314159265 can specify in the HEAD part of the document the following:
< link rel="canonical" href="http://example.com/page.html">
That tells search engines that the preferred location of this url (the “canonical” location, in search engine speak) is http://example.com/page.html instead of http://www.example.com/page.html?sid=asdf314159265 .

Reference:
http://www.mattcutts.com/blog/canonical-link-tag/


http://searchengineland.com/canonical-tag-16537


URL Referrer Tracking

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