Help:DEFAULTSORT

Brief overview
If an article is linked on a [Special:Category|category] page, it is sorted by its name by default. If the article should be sorted differently in a certain category the tag would be set. Alternatively the magic word DEFAULTSORT can be used to sort the article on any and all categories it is referred to on.

Example
Imagine there is a page called The Pirates Elite, which should be sorted under P rather than T. To change the string, which it is sorted by, set the default sort string like this:

Wikipedia link

 * DEFAULTSORT on the Wikipedia