This command forces everything which can be accessed from SuperBASIC to be cleared, killed or removed: Jobs, file definition blocks (except if Qjump’s Hotkey System is present), variables, the DATA pointer, the common heap and all channels are closed. On an Atari QL-Emulator and under SMS, the buffer for the serial and parallel port is also cleared.
Be very careful! All data will be lost. Avoid this command if you can: it is more like a safe emergency break.