Is this a modern take on Nancy Mitford's 'U and Non-U', published 60 years ago? For her, U meant upper-class and non-U the opposite. She offered one social instance which revealed which you were; namely, whether you put milk in your teacup before or after the tea. If you did so first, you were a MIF...a milk-in-first person and effectively the lowest of the low!
(If you ever use the word, MIF, be careful that it doesn't come out as MILF, which is something quite other!)