How do you tell sleeper cars apart?

Question

Like 10-6s, 6-5s, and etc.

Answer 1

Huh? a sleeper car is merely an average looking vehicle with above average performance.

Answer 2

On North American railroads the sleeping cars used to have names on them. Also a Dining car would have a name on it. Lounge cars usually had names on the sides also.Coaches had just numbers on it. Although at the end of each car there was also a number indicating the car number at the time, this number could easily be changed depending on the train.

Answer 3

By the window arrangement and the interior layout.

I'm a bit rusty, but the 6-5 is something like 6 drawing rooms 5 bed rooms.