part number letter prefixes

[musselmark]

what do the part number letter prefixes represent, for example a 2003 rx1 lists key switch as 8FA-82510-00-00 and my '07 venture lists it is as
8FJ-82510-00-00

could they be interchanged?

 

[yamaha1973]

yamaha has a very specific number system, for example all the igintion switches may have the middle five digits be 82510 but the first three indicate a different style switch, different part number = different part.... maybe interchangable dont know why they wouldnt

 

[darv]

the first 3 numbers or letters represent the model that that part is for.