This ETS specifies the data syntax to be used by Videotex services for terminal capabilities identification. This ETS is applicable to both the Videotex service and the attached Videotex terminals. Those terminals may be connected to the Videotex service via the Public Switched Telephone Network (PSTN) or the Integrated Services Digital Network (ISDN). Connection of terminals to other networks is for further study. It also applies to any equipment (e.g. another Videotex service) which acts as a Videotex terminal.