The military speaks in what's called the phonetic alphabet, especially on a radio. If you simply say the alphabet, letters like a, b, c, d, e, g, j, k, t, v, and z all sound alike. Cops and maintainers have their own versions, too.
Aircrew = A= Alpha.
Cops = A = Adam
Maintenance = A = Able
Canadians = A = Eh?
