Fokker-Jock,
Flew around for thousands of hours on all sorts of Boeings and always wondered what those damned things were for. Now, approaching retirement, you've solved one of the last great mysteries of aviation, and I can retire in peace. Kinda sad in a way though, like finding out that there's really no Santa Claus.
Hey! Before I go, what do you do if it's a 4 digit flight number ?