I found the code book sheet buried in some drawer that we were supposed to use at Brize for the ground runs but no one ever did and most didn't even know it existed, I cannot remember them, but it went something like this is aircraft 12 on bay c requesting the
trade 7 to the aircraft please, at which point you could almost hear the WTF is he talking about?
The Tens were like two numbers on from the last two in the serial.