Expression or writing in the common or conventional language indigenous to a population; being the plain language, native patois, mother tongue, or regional dialect of ordinary people. This holistic form of communication is "vulgar" in the sense of being prosaic, colloquial, customary, or unsophisticated. Standard regional references include: "Dictionary of American Regional English" (DARE); "Word Geography"; "Linguistic Atlas of New England"; and "Linguistic Atlas of the Upper Mid-West". Also, any distinctive language that identifies a class, profession, or other group, such as parlance, jargon, idiom, argot, lingo, cant, slang, or the like; as contrasted with multilingual diversity. See polyglot, lingua franca, pidgin, pig Latin, creole, mannerism, counterword, euphemism, ad diction, balderdash, language, sociolinguistics, orality, literature.