Springfield Armory XDm model suffix letters?

[Shinbone]

Does anyone know what the suffix letters represent at the end of various SA model numbers? For example, there is the XDM9384BHC, BTHC, CBHC and CSHC.
Thanks.

 

[CooterShooter]

I think I read or heard somewhere that SA and other manufacturers have started just recently to include more info about the specific factory where the handgun (only handguns) was produced, in compliance with legislation they were anticipating in the near future. I don't know of any recent laws or rumors of laws pertaining to this, so I doubt the credibility of that assumption. But then, maybe SA knows something we don't. If I find the source I'll post it here.