Makes categories required for specified channels category groups.
Developed by Wouter Vervloet, http://www.baseworks.nl/
BW Required Category is an ExpressionEngine 2 add-on and won't be ported to ExpressionEngine 1.x. If you are looking for a EE 1.x solution, I suggest you check out Designchuchi's DC Required Category as it equally (or even more) awesome.
Drop the entire bw_required_category folder in the third_party folder:
/system/expressionengine/third_party/bw_required_category/
After installing BW Required Category you set the channel preferences on the extension settings page. BW Required Category is either turned on or off for specific channel category groups.