Engine Codes

When ordering parts I was asked what "engine range" the part was for. I have never heard of an "engine range" and have never been asked this before when ordering parts and always got the correct part. Can someone please tell me what this means and where they are located? The choices they gave me were;

-12-078172
-10-030069
12-078173-
10-030070-

I looked everywhere in the engine bay, VIN placard, etc., could not find the above codes or even similar listed anywhere.

Thanks,

Rick

1993 - 190E 2.3
Engine W102.985
Chassis W201.028