What does Appropriate Use of Rel Canonical mean?

[smartapps]

I'm a newb and see this on my report and I don't understand what it means. Any help?

[Houses]

Hi,

You might find these pages useful:

http://moz.com/blog/rel-confused-answers-to-your-rel-canonical-questions

http://moz.com/blog/which-page-is-canonical

[MoosaHemani]

Short and simple! When you have two identical pages on your website and somehow you have to include both URLs for users, all you have to do is to include the rel canonical tag to the preferred version so that Google finds out that what the original page is and will rank accordingly.

Google will no rank both pages containing the same content but it will still b available for users and search engine will not hurt you for having a duplicate content on the website.

Hope this helps!

[WesleySmits]

The rel="canonical" attribute should be used when there is a set of pages with the same or highly similar content.
This could be for example a category page which lists the products in different orders on different pages with for example URL parameters. (http://www.example.com/products.html?order=popular VS http://www.example.com/products.html?order=newest)

It could also be product pages appearing several times at different URL's (http://www.example.com/product1.html AND http://www.example.com/category1/product1.html AND http://www.example.com/brand1/product1.html)

In both of these cases Google would index all versions of the page and duplicate content issues will arise. Duplicate content can really harm your rankings. In situations like this you could use the to indicate to Google that they should index the page listed in the canonical tag and not the one they are currently viewing.

More information on canonicalization and the rel="canonical" attribute

• <address>Moz: Canonicalization</address>

• Complete guide to Rel Canonical - How to and why (not)

[FedeEinhorn]

The canonical tag is used to tell search engine crawlers (Googlebot, Bing bot, etc) that the page they are viewing should be indexed using the value of the canonical tag.

Say the bot is crawling http://www.domain.com/page.html?var=1, a canonical there could have "http://www.domain.com/page.html" as the value to tell search engines that http://www.domain.com/page.html is the page they should be indexing.

It does not guarantee that the engine will in fact index that URL, but it helps avoiding duplicate content issues.

More here: https://support.google.com/webmasters/answer/139394?hl=en