This category lists CTU codes and protocols featured on 24.
“Flank 2 was a CTU coding protocol used prior to Day 5. CTU used the protocol "flank 2" as a code...Flank 2
“Wireless protocol was a protocol that CTU enacted when there was issues with their landline...Wireless protocol
“Level 5 protocol, a government security protocol initiated in certain extreme situations, was in...Level 5 protocol