You can specify a canonical URL in two ways:
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[*][B]Add a rel="canonical" link to the <head> section of the non-canonical version of each HTML page.[/B] To specify a canonical link to the page [URL]http://www.example.com/product.php?item=swedish-fish[/URL], create a <link> element as follows:
<link rel="canonical" href="http://www.example.com/product.php?item=swedish-fish"/>
[*]Copy this link into the <head> section of all non-canonical versions of the page, such as [URL]http://www.example.com/product.php?item=swedish-fish&sort=price[/URL].
If you publish content on both [URL]http://www.example.com/product.php?item=swedish-fish[/URL] and [URL]https://www.example.com/product.php?item=swedish-fish[/URL], you can specify the canonical version of the page. Create the <link> element:
<link rel="canonical" href="http://www.example.com/product.php?item=swedish-fish"/>
[*]Add this link to the <head> section of [URL]https://www.example.com/product.php?item=swedish-fish[/URL].
[*][B]Indicate the canonical version of a URL by responding with the Link rel="canonical" HTTP header.[/B] Adding rel="canonical" to the head section of a page is useful for HTML content, but it can't be used for PDFs and other [URL="https://support.google.com/webmasters/answer/answer.py?answer=35287"]file types indexed by Google Web Search[/URL]. In these cases you can indicate a canonical URL by responding with the Link rel="canonical" [URL="http://en.wikipedia.org/wiki/List_of_HTTP_header_fields"]HTTP header[/URL], like this (note that to use this option, you'll need to be able to configure your server):
Link: <http://www.example.com/downloads/white-paper.pdf>; rel="canonical"
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