Etiquette is a common practice in people's life and social interaction. People can correctly grasp the scale of interpersonal communication with the outside world according to various etiquette norms, and properly handle the relationship between good people and people.
Without these etiquette norms, people will often be at a loss in communication, and even be rude to others and make jokes. Therefore, if you are familiar with and master the etiquette, you can draw inferences from one example to another. As long as you pay attention to etiquette, everything will be done just right.