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"
“ A Diary Holder is a person capable of predicting the future via his or her Diary. Primarily...
“ Here's the current available versions of Diary Holders each users. This is the diary holders...