RACF supports a universal access facility for undefined terminals, which you can control by means of the SETROPTS TERMINAL command (provided you have the necessary authorization). When SETROPTS TERMINAL(NONE|READ) is in effect, it affects all MVS terminal subsystems.
If SETROPTS TERMINAL(READ) is in effect, RACF allows any user to log on at any undefined terminal (that is, a terminal not defined in the TERMINAL or GTERMINL resource classes). If SETROPTS TERMINAL(NONE) is in effect, RACF does not allow anyone to log on at any undefined terminal.