Idiosyncrasy

Idiosyncrasy comes from Greek ιδιοσυγκρασία "a peculiar temperament," "habit of body" (idios "one's own" and sun-krasis "mixture"). It is defined as a structural or behavioral characteristic peculiar to an individual or group.
The term can also be applied to symbols. Idiosyncratic symbols are symbols that may mean one thing for a particular person, as a blade could mean war, but to someone else, it could symbolize a knighting.