I wonder if they could provide measurable statistics for the first year of NATO alphabet vs recent years of phonetic alphabet. Watching railway safety vids from Britain, you get the impression a report is made every time an engineer sneezes on his control desk, so can't be that hard to draw up a comparison.

But, seriously, make overs on full duplex? Totally superfluous. Utterly needed on simplex and semi-duplex, though, to notify the other side that you are about to stop transmitting.

Simplex: Transmit/receive on same channel or frequency. No simultaneous tx/rx.
Semi-duplex: Transmit/receive on different frequencies. Still no simultaneous tx/rx.
Full duplex: Simultaneous transmit/receive on different frequencies.