This implementation rule applies to the compulsory certification of telecommunications terminal equipment. Telecommunications terminal equipment refers to telecommunications equipment connected at the end of a public telecommunications network to provide users with the function of sending and receiving information. Telecom terminal equipment in this implementation rule includes: fixed telephone terminals, cordless telephone terminals, group telephones, fax machines, modems (including cards), mobile user terminals, ISDN terminals, data terminals (including cards), multimedia terminal equipment, etc.