U and non-U English usage, where "U" stands for upper class, and "non-U" represents the aspiring middle classes, was part of the terminology of popular discourse of social dialects (sociolects) in Britain in the 1950s. The different vocabularies can often appear quite counter-intuitive: the middle classes prefer "fancy" or fashionable words, even neologisms and often euphemisms, in attempts to make themselves sound more refined ("posher than posh"), while the upper classes in many cases stick to the same plain and traditional words that the working classes also use, as, confident in the security of their social position, they have no need to seek to display refinement.

Ú, ú (u-acute) is a Latin letter used in the Czech, Faroese, Hungarian, Icelandic, and Slovak writing systems. This letter also appears in Dutch, Frisian, Irish, Occitan, Pinyin, Portuguese, Spanish, Italian, Galician, and Vietnamese as a variant of the letter "U".