The trains operating on the NRLA network bear all kinds of inscriptions. Indecipherable to the casual observer, they are of vital importance to rail operators and staff. The vehicle number is a unique identifier. For a double-deck coach operating through the Lötschberg, for example, it might look like this: Bt 50 85 26-94 934-4. The number contains information on the type of vehicle, the country of origin, the coach class, permitted speed and the heating system. Other data include the vehicle's weight and length, braking systems, top speed, voltages at which it can operate, and minimum curve radii. The signs, symbols, letters and numbers are all part of a much larger system. They are as essential to rail operations as the wheels on which the vehicles run.
« Trains and marshalling movements on the line are indicated by even numbers in one direction and odd numbers in the opposite direction. »FOT, Train Operating Regulations, «General information», p. 52, 01.07.2016