They have to have the name of the person/company that registered them as a NFA item
Engraving your name is done one NFA items that you reistered on form 1.
If you buy a that suppressor on form 4 it will have KAC's name and address engraved on it.
So, would receivers that are deemed to be Class III be the only NFA items that require engraving per a Form 1? I suppose a destructive device may too (I have no interest in those, though).