Social marker
A social marker is a discernible sign that gives a clue to a group identity of the person with the marker. It is frequently used by members of elite to indicate their dominant position through appearance, speech, dress, choice of food, and rituals of socializing, so called class markers.
The markers delimit the boundaries between the social groups, connecting a person to "in-group" people like them and at the same time separating from the "out-group" ones (unlike others).