remove -1 from category in url (alias)

I am reviewing my URL structure for ED categories and posts. I changed one of the aliases (from rrg-faq --> faq) but when i save it the alias becomes faq-1. I have read other posts about -1 being added because of duplicates but there is no ED category with that alias as far as I can see. If it happens because of an (old) other category having that same alias where in ED can I find these old or deprecated categories/aliases so I can remove them ??