On Monday, Allan Scott of Google posted a blog post on the Google Webmaster Blog which goes by the name of 5 common mistakes with rel=canonical.
To be more specific, the most common five canonical mistakes are:
- rel=canonical to the initial page of a paginated series
- Absolute URLs erroneously written as relative URLs
- Not deliberate or several declarations of rel=canonical
- Category or landing page specifies rel=canonical to a highlighted article
- rel=canonical in the body>
This is certainly an essential read for just about any developer, webmaster as well as site owner with a larger site. I suggest you check out the complete blog post, which includes images to enlighten all of it.