This month’s new wiki infrastructure update delivers a better way of selecting article categories. Rather than hoping you guess the right categories we now present group and list the key categories you’re likely to want to apply. 

You can also search for other categories in the search box (with autocomplete) or launch the "Category Chooser" to see all categories in the ontology or the wiki.

There is more information and guidance on category selection in the help topic: http://www.developer.nokia.com/Community/Wiki/Help:Categories