Yes It's RZM marked like on some SA loops.
So I did see and assume right. Up to now I have seen these RZM marked D-rings on RLB junior belt loops. They are commonly smaller and thinner than the "normal" (what in this hobby is "normal"
) SAloops and the "normal" SAloops have D-rings with at least one side pebbled.
Naturally a lot of variants do exist.
So the elongation is a totally mix up.