Bulbapedia:Categories
Categories are special links on a wiki that cause a page to be included in a group of pages about similar things. They are made by putting [[Category:(category name)]] or {{subst:Cat2|(category name)}} at the bottom of a page, most preferentially, but they will technically work anywhere on a page.
Categories are used in order to make everything on a wiki easier to find, and to allow related articles to be accessed easily. On Bulbapedia, it is official policy for every page to be categorized, with the notable exception of the Main Page.
In order to link to a category on a page with normal text and not categorize said page in that category, one must either put a colon before the Category namespace tag ([[:Category:(category name)]]) or use the {{cat}} link template, which shortens the job.
