"The Terminal Facility Indentifier may be used to ascertain the capabilities of a ""terminal""@ (where a terminal may actually be a physical terminal or another videotex service). The TFI may be used in three ways: 1) To determine the terminal profile and additional terminal capabilities; 2) To determine to which parts of the Service Reference Model (SRM) the terminal conforms; 3) To determine whether the terminal can execute a particular Videotex Persentation Data Element (VPDE)."