Among the souvenirs etc. my Father sent home while he was in WWII was a single page telling them how to behave while in Great Britain. This was given to them the same day they landed in Liverpool.
One thing was not to show off your wealth as if something like $18 a month was a lot of wealth.
Also they were told not to complain about their coffee. “After all they think we can’t make a decent cup of tea.”
From this?
"The little book that gave American GIs their first taste of England during WW II"