Q-Codes;- a brilliant, ground-breaking idea - in 1909. Possibly not that relevant, or even useful, more than a century later? Discuss.
QFE? Ridiculous.
It is interesting to note in the 1949 Air Ministry book of Q Codes that QNH did not exist at that time! The two pressures used were QFE, surface pressure at an aerodrome and QFF, pressure at mean sea level. QNH first appeared in the eraly 1950s following an amendment to the method of determing the Sea Level Pressure when not at sea level.