Holy Office of the Cardinal
From DQWiki
The teaching of magic, alchemy, & healing is strictly controlled by the Holy Office of the Cardinal (or the Bishop in the overseas possessions), which licenses all magic-users, including any visitors who wish to practise magic.
Watermages, Airmages, Celestials, & Namers represent 95% of all mages -- and the other 5% are assumed to be E&Es, even when they aren’t.
About 70% of Dons are magic-users; non-mages are usually in the military or officials, often inheriting the status rather than earning it.