ISPF gives you access to the MVS/TSO operating system by letting you enter TSO commands, CLISTs, and REXX EXECs from within ISPF. z/OS TSO/E Command Reference contains descriptions of all TSO commands.

You can enter most TSO commands, CLISTs, and REXX EXECs from all three panel types: data entry; menu; and scrollable data display. However, some TSO commands, such as LOGON and LOGOFF, can cause unwanted results when you enter them from ISPF. This is also true of CLISTs and REXX EXECs that contain these TSO commands. The rules for entering TSO Commands, CLISTs and REXX EXECS are described in the Command (Option 6) topic in the z/OS ISPF User's Guide Vol II.