I have been on one sleeper train but that was sort of a unique experience in 1980. Nothing since.
I have to ride one in about 3 weeks, not looking forward to it.
Looks like I have an upper berth in a 4-berth compartment.
Two will be strangers that probably dont speak much if any English, one will ... not exactly a close acquaintance. And it’s co-ed. Leaves at 8pm arrives at 7am. Not exactly how I want to spend 22 hours of my life, but what the he!!, you only live once.
So, any etiquette I need to know about?
Found these:
https://travel.stackexchange.com/questions/140851/etiquette-when-sharing-a-sleeping-car-room-with-stranger-in-europe
https://www.internationaltraveller.com/world/sleeper-trains/