Wiktionary
control code
n. (context computing English) A numeric value or string of such values such as a simple control character or escape character character which causes some other specific commanded or requested action to occur, which would not otherwise be accessible to a user or device generating the code.
Usage examples of "control code".
Let Roquelaure and his people have the damned control code, or whatever they want from you.
He coasted up to it and gently touched a control code to the surface.
He had the number and control code for the new Swiss account, and in that was enough money to support him for the rest of his life.