I had a 335d for demo a few weeks ago. Got given something very similar by stealer.
A few years ago in my previous role I got talking to a BMW automation engineer. He was telling me how they were going to write code and keep track of what was going on the line. He'd mentioned the three digit codes. What was interesting at the time was that a lot of the data was being ported via a an integrated web server to SAP. So that also the ordering process management could check current status of car build.
This probably sounds normal nowadays but automation technology is always lagging behind everything else as it has to gain acceptance. BMW have always been keen to try new ideas. As many of my employers products exist because of demand from the 3er BMW.
I can't see whay you would want to designate M Sport and SE as its easier to track the component changes between the two (just in case you decide to stop fitting certain items).
New Company car 2011 BMW F10 520D SE Xirallic Imperial blue/Cinnamon Brown 6FL USB, Front Sports seats, Sports steering wheel, Xenons - Arrived 3rd Dec 2010!
Scrapped RIP 12/08/2010 - E90 320si - Le Mans Blue - Totally standard specification
Long gone - 00 Peugeot 306 2.0 SE Cabriolet, 94 Rover 214 SEi, 91 Fiat Uno 60S Mk2