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
QWERTY or based on the English (US) keyboard. In Windows 8 and later versions, the backslash key (left of Z or space) is duplicated onto the hash key (left of Enter), press which with key to type backslash , with and keys to type vertical bar . This aids users who are familiar with UK keyboard layout while the keyboard lacks this key (e.g. US Standard keyboard and Japan JIS keyboard). The British version of the Apple Keyboard does not use the standard UK layout. Instead, some older versions have the US layout (see below) with a few differences: the sign