WordPress gives us an awesome way to control the structure of the base URL’s of our blog with the name called Permalinks. It allows us to specify custom permalink structure for our urls, so we can have an easy to remember and user friendly URL’s across our site.
However, the default install of WordPress will add the word “category” to your url structure before the actual category name. Having /category/ in the url of your blog url isn’t very useful, you could end up with a very unattractive permalink and it will make the URL longer and harder to remember. Keep in mind that URL’s are an important part of SEO.
Rel Nofollow Categories is a plugin which adds nofollow attribute to categories generated by the_category and wp_list_categories throughout the blog. The plugin will just add rel nofollow attribute to category links but still let the search engines, such as google, yahoo, bing etc…, index your Category pages.
This is useful when you just want your Post page to have a higher PR (Pagerank) than those of Category pages.