Behaviour or beliefs that are so far outside the norms that they generate very strong negative reactions from others, e.g. being extremely heavily tattooed or pierced, claiming to have been abducted by aliens
Do not have official status, but friends, family members and workmates may apply negative sanctions (such as playing practical jokes on someone or ridiculing them) to those caught breaking unwritten rules
Informal rules apply to everyone in different ways, for example children and adults may be expected to behave differently in a supermarket checkout queue, and there may be different expectations about how men and women should dress for a job interview