Bullfighting - under "Society and Culture" - I found it by accident - I wonder how many other categories there are that don't show up this way. It does not appear to be in any index.
http://answers.yahoo.com/dir/index;_ylt=AqFKDPibpZQyMg0oEyKy1fbc7BR.;_ylv=3?link=ask&sid=396547050
Betwixt & Between
Favorite Answer
That's because they deleted that category.
In order to keep record for everyone's answers/best answers in this category though, they have to keep it in a type of sub-existence. The difference, though, is like you said .. it's not on the index, & you cannot post a question in it.
Anonymous
I have found similar anomalies. If you look on yahoo Australia you will see there is no link to Yahoo! Products> Yahoo! Answers.