We found that every inner category pages of WordPress should contain a canonical tag pointing to itself rather than pointing to the first page of the category as below:
<link rel="canonical" href="http://www.example.com/category-article-part5"/>
<link rel="prev" href="http://www.example.com/category-article-part4" />
<link rel="next" href="http://www.example.com/category-article-part6" />
This is what Google encourages to do. Google says that we should only use a Canonical tag to avoid duplicate content. However, in a paginated category page of WordPress, there are no duplicates. The best solution is to point every paginated category page to itself.
Here is what Google said:
rel="prev"are compatible with
rel="canonical"values. You can include both declarations in the same page. For example, a page can contain both of the following HTML tags:
<link rel=”canonical” href=”http://www.example.com/article”/> <link rel=”next” href=”http://www.example.com/article-part2″ />
Let’s understand the code, the page URL is http://www.example.com/article the next paginated page is http://www.example.com/article-part2
Then, we found the following in the Google webmaster blog:
Mistake 1: rel=canonical to the first page of a paginated series
Imagine that you have an article that spans several pages:example.com/article?story=cupcake-news&page=1
and so on
Specifying a rel=canonical from page 2 (or any later page) to page 1 is not correct use of rel=canonical, as these are not duplicate pages. Using rel=canonical in this instance would result in the content on pages 2 and beyond not being indexed at all.