Correct Implementation Of Canonical Tags

[ZaddleMarketing]

Hopefully this is an easy one to answer.

When canonical tags are added to web pages should there be a canonical tag on a page that canonicalizes(?) (new word!?) back to itself.

i.e. four page all point back to page Z. On page Z there is a canonical tag that points to page Z?

My feeling without any technical know how is that this is just creating an infinite loop i.e. go to this page for original content, (repeat)

Or this could be completely correct!

Don't want to go back to the developer and point out the error if I'm wrong!

[Sarbs]

You can canoncical to the same page yes, i saw a video or blog from Matt Cutts just the other week confirming this but cant for the life of me find it again now. Will pop the link on here if i find it unless anyone else in the community can provide confirmation before hand.

[TomRayner]

Hey there

Having a self referring canonical tag, as it were, is something I'd recommend for a couple of reasons.

As you have pointed out, canonical tags can help remove the chance of other duplicate pages getting indexed.  However, Google will indexes URLs and one physical page can have a number of different URLs.  For example, if your website has a search function of anything else that might produce a query string (like domain.com/page?query), these URLs can also be indexed and would be seen as duplicate content by Google.

There would not be a physical page to apply the tag to, but if you add a self referring canonical tag, any dynamic URL that is generated by your CMS should not be indexed, helping to limit the chance of any duplicate content penalty.

Furthermore, I believe that having a tag on your page protects you somewhat from scrapers and people stealing your content.  If your page is indexed first with your tag, any syndicated or duplicate versions from 3rd parties in theory should not be able to rank that content.

You look at places like Search Engine Land and they have these self referring canonicals too.

Hope this helps. Enjoy your weekend!

[ZaddleMarketing]

Awesome - thanks for the quick responses!

[Ticket_King]

I think that this is the video that was mentioned by Rich. It goes back to 2011. Matt does say that he can't account for other search engines, but Google is cool with using a rel="canonincal" tag to point to "itself."