QNE - Altitude above MSL at standard setting of 1013 (used when above 3000ft, only if dealing with ATC)
QNE is
not an altimeter setting, it is the indication on the altimeter when landing at an aerodrome with the Standard Pressure Setting set on the sub scale. It is used at high altitude airports where QFE is too low to be set on the sub scale. QNE has nothing whatever to do with 'Altitude above MSL', it is not 'used when above 3000ft' or 'only if dealing with ATC'.
QFE is the observed pressure at a reference datum (usually the aerodrome reference point or landing threshold) which, when set on the altimeter sub scale, will indicate
height above the reference datum.
QNH is the observed pressure at a location adjusted, using the standard atmosphere, to mean sea level which, when set on an altimeter sub scale, will indicate
altitude above MSL.
When set to a pressure of 1013.2 hPa an altimeter will indicate
flight level