class distinction
/ˌklɑːs dɪˈstɪŋ(k)ʃn/ /ˌklas dɪˈstɪŋ(k)ʃn/noun
1The differentiation of one social class from another; (also) a point of differentiation between social classes, as a characteristic attitude, behaviour, etc.
2A distinction between two classes of objects; (also) a distinction between two objects on the basis of their membership of different classes.
Origin
Early 19th century. From class + distinction.