A term used in sociolinguistics and stylistics to refer to any system of linguistic expression whose use is governed by situational variables. In some cases, the situational distinctiveness of the language may be easily stated, as in many regional and occupational varieties (e.g. London English, religious English); in other cases, as in studies of social class, the varieties are more difficult to define, involving the intersection of several variables (e.g. sex, age, occupation). Several classifications of language varieties have been proposed, involving such terms as dialect, register, medium and field. For some sociolinguists, ‘variety’ is given a more restricted definition, as one kind of situational distinctive language - a specialized type of language used within a dialect, e.g. for occupational purposes.