Cut, copy, and paste Apple mapped the functionalities to key combinations consisting of the Command key (a special modifier key) held down while typing the letters X (for cut), C (for copy), and V (for paste), choosing a handful of keyboard shortcuts to control basic editing operations. The keys involved all cluster together at the left end of the bottom row of the standard QWERTY keyboard, and each key is combined with a special modifier key to perform the desired operation: The IBM Common User Access (CUA) standard also uses combinations of the Insert, Del, Shift and Control keys. Early versions of Windows used
Magic SysRq key are means to forcibly unmount file systems, kill processes, recover keyboard state, and write unwritten data to disk. With respect to these tasks, this feature serves as a tool of last resort. The magic SysRq key cannot work under certain conditions, such as a kernel panic or a hardware failure preventing the kernel from running properly. The key combination consists of and another key, which controls the command issued. The combinations always assume the QWERTY keyboard layout; for example, on a Dvorak Simplified Keyboard, the combination to shut the system down uses the key instead of . Furthermore, some keyboards