Substitute character actions than the last one can also be undone by pressing multiple times. was one of a handful of keyboard sequences chosen by the program designers at Xerox PARC to control text editing. Presumably these particular keystrokes were chosen because of their location on a standard QWERTY keyboard, since the Z (undo), X (cut), C (copy), and V (paste) keys are located together at the left end of the bottom row of the standard QWERTY keyboard. Substitute character A substitute character (␚) is a control character that is used in the place of a character that is recognized to be
Keyboard layout keys (this however includes more processing from the keyboard hardware, and can therefore be slightly slower, with a lag that may be noticed in daily use). A few companies offer "ABC" (alphabetical) layout keyboards. Some keyboard layouts for non-Latin alphabetic scripts, most notably the Greek layout, are based on the QWERTY layout, in that glyphs are assigned as far as possible to keys that bear similar-sounding or appearing glyphs in QWERTY. This saves learning time for those familiar with QWERTY, and eases entry of Latin characters (with QWERTY) as well for Greek users. This is not a general rule, and