Q codes
When I trained back in the sixties the number of Q codes which the then skippers used amazed me. Obviously, I assumed, left over from the war.
When I retired those in use were down to single figures. Obviously QFE (although BA dumped using it ages ago), QNH, QDM etc are still in use, but what about the others?
For example using QSY (I think that is correct) rather than "I am changing/ would like to change frequency" seemed to save RT clutter.
There must be loads of other forgotten (but useful) Q codes out there...
Over to you........