Can any member help identify the part numbers on Siemans SID units or suggest where I can get the information

example:- Numbers on Siemans SID201
5WS40059H-T what does each digit mean partcularly the last two
I think 4R8Q-12A650-EF

I can find anywhere that these are listed, 12A650 seems to be the series but 4R8Q and EF???/

this information would help a lot of owners, also is there reference manufacturers??
as there seems to be several used on the same models

I am trying to find out what units can interchanged and re-programed and used as donors to other vehicles.

thanks for your help

stan