Search Engine Optimization

Google, Microsoft and Yahoo united on the new canonical link tag. From Search Engine Land Vanessa Fox reports:

• Today, Google, Yahoo and Microsoft (links are to their separate announcements) have united to offer a way to reduce duplicate content clutter and make things easier for everyone.

Example of cannonical link tag:

<link rel=”canonical” href=”http://www.example.com/product.php?item=swedish-fish”/>

Why Use Canonical Tag?

Dynamic websites tend to produce multiple URLs for the exact content, causing search engines to flag domains with duplicate content penalties or causing crawl bot abandon website altogether. Canonical tag will hint search engines that URL is absolute, and should be considered over others, while bot can ignore other URLs.

There are some rules to the tag:

• You can only use the tag on pages within a single site (subdomains and subfolders are fine).
• You can use relative or absolute links, but the search engines recommend absolute links.

This tag will operate in a similar way to a 301 redirect for all URLs that display the page with this tag.

• Links to all URLs will be consolidated to the one specified as canonical.
• Search engines will consider this URL a “strong hint” as to the one to crawl and index.

Vanessa Fox does good coverage of the topic and we recommend you read more to learn about this new tag in detail.