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"
“ (Update: The desired feature has essentially been provided in the form of the ASCII template...
“ Pages that were in this category should be in Category:SSSS. This category page should be empty...
“ This category's subcategories collect pages etc. that have been "checked". The DPLforum...
“ This is a list of topics from Forum:Help desk. For other sources of help, please see Category:Help.