In late 30's and early 40's, US Army was one of very few armed forces in teh world that allowed shirts to be worn as official uniform, without coats. As I understand it, officers wore rank insignia on shoulders (officer's shirts had epaulettes, enlisted men's didn't) and US and branch insignia on the collar. Can anyone tell me when was the wearing of rank insignia on shirt shoulders discontinued? Because, at some point rank insignia moved to one side of the shirt collar (in place of US insignia). Also, I would like to know what was the official regulation regarding shirt collar insignia when shirt was worn with coat (so-called officer's pinks & greens)?Also, I noticed that ties weren always worn with the shirt, so I'd like to know the official regulations regarding that.
I would greatly appreciate any information about this! Thank you