Wikipedia:Categories Sorting
When placing pages in categories, it is important that they be sorted correctly. This makes it easier to locate a page in the category. Sorting of pages in a category is done by use of a 'sort key'. A sort key is a term or phrase that is used to sort pages in categories. Pages are sorted alpha-numerically by their sort key. If no sort key is used, the page name of the page is used as the default sort key. Sort keys may be given to each category tag individually.