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 two major forms of keyboard layouts: Dubeolsik (두벌식), and Sebeolsik (세벌식). Dubeolsik, which shares its symbol layout with the QWERTY keyboard, is much more commonly used. While Korean consonants and vowels ("jamo") are grouped together into syllabic grids when written, the script is essentially alphabetical, and therefore typing in Korean is quite simple for those who understand the Korean alphabet Hangul. Each "jamo" is assigned to a single key. As the user types letters, the computer automatically groups them into syllabic characters. Given a sequence of "jamo", there is only one unambiguous way letters can be validly grouped into syllables,