The Compose() action allows the input of accented or APL characters on keyboards that do not directly support them.
Pressing a key mapped to Compose(), then pressing two other keys in succession, inputs a character composed of those two keys.
The rules for composed characters are controlled by the current compose map.
|3270||Multi*||Ctrl-a + m||Alt-m|
|NVT||Multi*||Ctrl-a + m||Alt-m|
Notes for x3270
*Multi is the Compose key, which does not exist on most modern keyboards (nor do most X11 servers map any key to this keysym).
The various "dead" keys on European keyboards are mapped onto sequences that include Compose(). E.g., <Key>dead_grave is mapped onto Compose() followed by Key(grave).