Canonical URLs are very important to avoid duplicate content penalties from Google. Before explaining, how to implement Canonical URLs in different CMS platforms – Lets understand what is canonicalization?
Canonicalization, is just a term used by Google to elaborate a process of selecting best URL for a particular web page, when there are several choices. In different CMS Softwares, if you select multiple categories for a single post, it may create multiple URLs for same content. For Example: site.com/category1/samplepost and site.com/category2/samplepost. So to avoid this duplicate content (in excerpts too), using canonical URL is the best option.
How to implement canonical URLs:
- Choose best URL (category) for a single post.
- Add this url as canonical URL for other categories with same content (in header section).
<link href="http://www.site.com/category1/samplepost”" rel="”canonical”"/>