control character

A character whose occurrence in a specific context initiates, modifies, or stops a control function (an operation to control a device, for example, in moving a cursor or in reading data). Control character have values below ASCII 32 in the ASCII character set. In a 4GL program, some control characters have predefined functions (pressing CONTROL-W obtains on-line Help). The developer can also define actions that use CONTROL keys in conjunction with another key to execute some programming action.

See also activation key, ASCII, character, logical key, modifier key.