Original Grey Technic motor from 1977: 6216a

[Santeri Piippo]

The 'm' suffix was used 'back in the day' because this is one case where there is conflct between DesignID numbers and Part numbers. DesignID 6216 is Brick 2 x 4 x 2 with Curved Top but 6216 was also used by LEGO to describe the part assembly which is this motor.
I have deferred finding a solution for this for too long, so now is maybe the time to find a solution.

I agree with Steffen about the a, b, c... suffix. Isn't that what we use when there's two colliding IDs?