When you want to put an article into that category, you don't have to literally add the category at the bottom of the page. Instead, you put a Spoiler Template on the top of the page when you edit the article. The category will then appear automatically. Remember that from now on.
Make sure to change your default editor to Source Mode in the Special:Preferences page, Editing tab. Source Mode is the only editing mode allowed in this wiki, as Visual Mode is not allowed due to the high number of glitches and problems it has caused.
Remember that you should sign all comments on talk and vote pages with four tildes (~~~~) to create your signature. You don't have to sign your comments on comment pages.
If you have any questions or discussion topics you wish to raise, don't forget to visit the Forum. You can also ask the admins any questions you may have.