Norwegian train car designation shorthand (incomplete).

B: Class B (which is the only class these days. So, meaning passenger seats)
M: Motorized (implies S. See below)
S: Steering capability
L: cargo space ("Lasterom")
C: Special capability of some sort, such as wheelchair ramp.
MU: Motorized car without driver capability (As in M without S)
P: Car with a pantagraph
R: Restaurant/bistro

So, for example, type 92 is a small set consisting of only two cars: A BM and a BS. Both cars have seating, the train can be controlled from both ends, but only one of them has a motor.

T93 is similar in layout.

T74 and T75 are both five-car trains, and I don't remember all of the cars, but I remember the middle of them is called BCMU or something like that.

The older T3 trains (now retired, I think), has a car designated LCR (or a different order), which means cargo space, food service, and some sort of special amenities that I never figured out. This train type also had class A with seating of a higher comfort level.

All of these types are printed on the side, usually next to a number, which is an internal serial number. So a 9214BM* means "Type 92, number 14, motor carriage (with passenger seating)".

*: I don't remember the exact syntax, but it's something like that.

EDIT: Un-fun fact I just realized long after using 9214 as an example above: It doesn'texist anymore.