Blue Stuff,
In my previous military incarnation I worked in an army trade where a working knowledge of the more common Q and Z codes was essential. Why not try what I did - do a Google search for "Morse Q codes"? It threw back over 5000 replies, showing that the aviation use might be dying out but the radio hams still love the brevity of the things.
For some reason, the code QRM ("I am being manually interfered with", followed by a number from 1 to 5 showing the strength of interference) springs back to mind... Strange people, those signallers.