I recently obtained formal qualifications to teach Latin (and mathematics and physics) in a number of Finnish schools and I got my diploma yesterday. How should I go about expressing this in Latin? Is there a good translation for "qualifications" (which I would use together with "teacher's" or "pedagogical")? Or would it be best to go with something like mihi linguam Latinam docere licet (which does not seem to communicate the formal qualifications)?
While I know a lot of people in several countries who have such formal qualifications to teach aut maths and physics aut Latin (symmetric difference) in various schools, you are the only person I know of who has them for et Latin et maths and physics (intersection). So congratulations!
On the other hand, my mother got her abilitazione to teach Latin in Italian upper schools in the 1950’s. For that, she had to write an original essay in Latin (quantum mutata tempora!), and the glorious dictionary she used is in my hands right now: Luigi Luciano, Nuovissimo Vocabolario Fraseologico Italiano-Latino, G.B. Paravia & C., Torino, 1924. (Fraseologico is the key: the focus is on translating phrases, not words.)
The formal Italian name of that qualification was, and still is, abilitazione all’insegnamento. Luciano has no translation for it, but it does translate the verb abilitare all’insegnamento: “Ius docendi concedere (alicui)” and the participle abilitato all’insegnamento: “Cui ius docendi concessum est.”
Any term you choose is loaded of different meaning in different countries. Idoneitas, for instance, would have no specific meaning for Italian high-school teachers, but academics would understand it as the particular step in their career when the State has already declared that they can be professors, but no University has called them for the post yet.
As always with recens latinitas, you have to choose what you want: either a general term to capture most equivalent terminology in as many countries as possible, or just Latin shapes for the different national terms.
My 2¢, or my II𐆚 if you prefer: use concessio iuris docendi.