All MAK 90s are postban. They are imported guns so they have to meet postban regulations put in place by daddy Bush's "sporting purposes only" ban of '89. Hence the name MAK 90. (MAK=Modified AK 1990)
Also, the year manufactured (or impored, I forget) is the first two digits of the serial number on MAK 90s.
Domestic makers don't have to worry about the '89 ban as that is an importation regulation. The '94 ban applies to all, but is not as harsh as the '89 ban. The '94 allows a detachable mag and 1 evil feature, whereas the '89 doesn't allow any evil features. This is how ARs can still have a pistol grip and a M1A can still have a flash suppressor. A MAK 90 offically has no evil features beyond the detachable magazine, as at that time, the ATF didn't classify a thumbhole as a pistol grip. (which they do now)
This is how adding US parts gets you a pistol grip on these guns. Once you reduce the number of imported parts (there are 20 offically listed parts that make up a gun) to 10 or less, it officially becomes domestic. Once that happens, you can add an evil feature as you get out of the '89 regs and into the '94.
What a bunch of crap!