This word is a coined word which connecting "net" and "etiquette". As our daily life, there are some manners in internet activities. Unlike the real life, people can communicate with other people without seeing other's expression at internet so that people sometimes tend to be very offensive to other people. With spreading of the internet usage, many problem raised such as slander and libel at internet BBS or spreading many hate speech all over the internet. In addition to these commonsensical etiquette, there are peculiar problem which could only seen at internet such as chain mail or spam mail. These problems are result of increase of commercial internet usage. Of course, people should care for people who communicate through internet but excessive commercial use at internet must be controlled by authority in order to maintain internet peace and order.