“I began to protest, but he cut me short. ‘A PLONGEUR with a moustache —nonsense! Take care I don’t see you with it tomorrow.’
On the way home I asked Boris what this meant. He shrugged his shoulders. ‘You must do what he says, MON AMI. No one in the hotel wears a moustache, except the cooks. I should have thought you would have noticed it. Reason? There is no reason. It is the custom.’
I saw that it was an etiquette, like not wearing a white tie with a dinner-jacket, and shaved off my moustache. Afterwards I found out the explanation of the custom, which is this: waiters in good hotels do not wear moustaches, and to show their superiority they decree that PLONGEURS shall not wear them either; and the cooks wear their moustaches to show their contempt for the waiters.”

George Orwell, ‘Down and Out in Paris and London’ 1933