ISO/IEC 9995-7 designed a graphical symbol for this key, in ISO/IEC 9995-7 as symbol 15 'Compose Character', and in ISO 7000 'Graphical symbols for use on equipment' as symbol ISO-7000-2021. On the keyboards of Sun Type 5 and 6 workstations, the Compose LED is placed in the keycap (see picture below). In 1987, Sun Microsystems released the Sun4, the first dedicated Unix workstation that had a compose key. While the LK201 introduced the group of command keys between the alphanumerical block and the numerical keypad, and the 'inverted T' arrangement of arrow keys, which have become standard, the compose key by contrast did not become a standard. The keyboard included an LED indicating that a Compose sequence is on-going.

The Compose Character key was introduced by engineers at Digital Equipment Corporation (DEC) on the LK201 keyboard, available since 1983 with the VT220 terminal. įor instance, typing Compose followed by ~ and then n will insert ñ.Ĭompose keys are most popular on Linux and other systems using the X Window System, but software exists to implement them on Windows and macOS. Xfce keyboard layout settings window, featuring a compose-key optionĪ compose key (sometimes called multi key) is a key on a computer keyboard that indicates that the following (usually 2 or more) keystrokes trigger the insertion of an alternate character, typically a precomposed character or a symbol.

Infinity symbol on keyboard windows 8