Social nonconformity is when a person behaves or acts in a way that goes against the standard or norm of a society. A norm is an unwritten rule shared by a group that governs their behavior. Norms define what behavior and actions are acceptable. An example of a norm is standing frontward facing the door in an elevator instead of facing the back wall and the people behind you. Another is not picking your nose in public.
Social nonconformists don't follow a social norm either deliberately or unintentionally. Social nonconformity can range from general inconsiderate behavior (such as talking on your phone during a movie) to lifestyles that may be judged or ostracized by others (like being a nudist). Norms are generally shared with others in your social group and wider culture. Norms within one group can be considered as social nonconformity by another group. For example, norms and social behaviors that are considered positive within criminal culture (such as violence and criminal activity) would be considered deviant nonconformist behavior from the majority of people.