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Google SEO updates summary
Canonical link element:
Category: Index inclusion
What is it? The canonical link element rel=”canonical” is added to a page within the header () of a page, typically by developers, as follows
This provides a hint to a search engine about which is the most important or original page if pages are identical or similar in terms of content, but have a different URL. Different URLs with similar content are common in these situations:
Tracking ids added to the query string:
Session ids added to the query string:
Faceted search parameters for advanced search engines::
The canonical link element was announced simultaneously (and is supported by) by Google, Yahoo! and Microsoft Live search engines.
Why is it significant? Many sites suffer from duplicate content, i.e. additional pages that may be stored or excluded from the Google Index. This is a problem since it effectively dilutes the impact of your pages since Google may flow the value it attributes to your site (through PageRank) around more pages rather than keeping it focused on the ones you want to rank. Using rel=canonical effectively flows the ranking from internal and potentially external links back to a single page. It may also mean that less relevant pages are displayed in the search index for users.
Note that this doesn’t help across domains/sites, for example for syndicated content such as press releases.
What should you do? Ask your SEO company or technical team whether they are auditing and then minimising duplicate content through using rel=canonical or other measures such as excluding duplicates through robots.txt.
More information / How Tos: