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 holding a modifier key with one hand leaves the other hand free to strike another key. An alphanumeric key labeled with only a single letter (usually the capital form) can generally be struck to type either a lower case or capital letter, the latter requiring the simultaneous holding of the key. The key is also used to type the upper of two symbols engraved on a given key, the lower being typed without using the modifier key. The English alphanumeric keyboard has a dedicated key for each of the letters A–Z, along with keys for punctuation and other symbols. In