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
Computer keyboard were compromised to allow for the mechanical limitations of the typewriter. As the letter-keys were attached to levers that needed to move freely, inventor Christopher Sholes developed the QWERTY layout to reduce the likelihood of jamming. With the advent of computers, lever jams are no longer an issue, but nevertheless, QWERTY layouts were adopted for electronic keyboards because they were widely used. Alternative layouts such as the Dvorak Simplified Keyboard are not in widespread use. The QWERTZ layout is widely used in Germany and much of Central Europe. The main difference between it and QWERTY is that Y and Z