I'm not aware of any US states that have a graded A, B, C, D system with courses and qualifications -- instead, they just ban everything that might be in a European B or C classification. This is how the old federal AWB worked, as well -- it didn't say, you can purchase an AR-15 if you take certain classes, it said you just can't buy it at all.

The European system, broadly speaking, is not like that.

There are federal classes for dealers and manufacturers -- manufacturers of silencers, of automatic weapons, of missiles and rockets, &c, and dealers of these articles -- but that also is not like the European classification system I am talking about, which is for end users.

The NFA, which does apply special regulation to silencers, short-barreled rifles and some other items, which allows them to be owned by end users, and that is kind of similar but there is a real difference: you file for a tax stamp and wait for a background check to complete, without having to worry about taking a particular course and getting a certain grade.