I recently acquired the 9c after performing my due deligence on this site and all across the Web. I have seen a few references to the serial number sequence in various threads. For example the one I own is an MPLxxxx and I see references to the MPM and MPN, is there a difference in the manufacturing process? did they (Smith) make changes along the way? Or is this simply the same way many others account for production runs? Thanks for the help and I appreciate the collective wisdom of this site.