Etiquette
Etiquette, one aspect of decorum, is a code that rules how everyone is expected to behave, according to the social conventions and norms, in society, in a social class, or group. It is usually unwritten, but it may be put in written form. Because they are a product of the society's culture and history, the rules of etiquette are very different from time to time, and from one place and social group to another.