Star Trek: 10 Secrets Of The Original Enterprise You Need To Know
6. The Enterprise's Self-Destruct Code
The code for the ship's auto-destruct was consistent throughout the series and films. It was segmented into three orders. Each code was recited by members of the bridge crew. The Captain, first officer, and second officer would give each order.
Destruct sequence 1: code 1-1A,
Destruct sequence 2: code 1-1A-2B,
Destruct sequence 3: code 1-B-2-B-3.
We see this code used twice on the screen. Once in the original series episode, “Let This Be Your Last Battlefield. The second time was in “Star Trek III: The Search for Spock," when the ship was actually destroyed.