coded information uses a system of words, letters or symbols instead of ordinary writing so that it can only be understood by someone else who knows the system:
He sent a coded message to CIA headquarters.
having a set of numbers, letters, or symbols to show what something is or give information about it:
The wires are colour coded for easy identification.
coded language expresses your opinion in an indirect way because it will probably offend someone:
They voiced their criticism in coded statements.
coded sounds or signals can only be understood by special machines:
coded signals broadcast by the BBC radio transmitters