Very often i see aircraft rated into Categories like A1, A3, A4 etc.
Is there somewhere an overview available where the different categories are documented?
So far i was not able to identify a pattern which explain it.
Currently i have for example a B737 on my screen documented as A0, an Airbus A400M as A4 and a B748 as A5
But there are also B737 documented as A3
