To add a new category to a page you can click the Category button at the bottom of the page and type in the name you'd like your category to be called.
A full list of existing categories can be found at Special:Categories.
Pages in category "Browse"
“ In order to maintain the articles clean and neatly organized, all wikis have a manual of style...
Phi Brain:Kami no Puzzle Wiki:Manual of Style
“ Here you can find a list of this Wiki's rules. Do not vandalize current articles or user pages...
Phi Brain:Kami no Puzzle Wiki:Policies