Dresscode on Commercial flights in First Class
What was first class travel dresscode when it applied, like 1950-s, 1960-s?
Was it enforced - i. e. were people with paid tickets liable to be denied boarding or involuntarily downgraded for failure to meet dresscode?
When did the men only flights operate (so that men could remove their jackets - since stewardesses count as "maidservants" rather than "ladies", and are not entitled to the same courtesy)?
When did dresscode on commercial flights disappear? (In which countries?)