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"
“ I have just added a option for defense cards to use with Template:CardWrap. It has slighty...
“ This page is a candidate for deletion. Remember to check what links here and the page history...
Candidates for deletion
“ This category contains disambiguation pages — navigational aids which list other pages that...
“ For a full list of help pages, see Help:Contents, which includes help pages shared across Wikia.