My understanding of QNE is what is stated in the UK Mats Part 1...
During conditions of exceptionally low atmospheric pressure it is not possible to set QFE or QNH on some aircraft altimeters. In these circumstances an aerodrome or runway QNE can be requested. The QNE is the reading in feet on an altimeter with the sub-scale set to 1013.2 hPa when the aircraft is at aerodrome or touchdown elevation.
This is backed up by the Wiki page which lists all of the Q-Codes and their meaning, which lists QNE as...
What indication will my altimeter give on landing at ____ (place) at ____ hours, my sub-scale being set to 1013.2 millibars (29.92 inches)?
After some recent conversations and after a few Google searches it would appear that there is an alternative definition where QNE is a way of referring to the Standard Pressure Setting. This appears to be widely accepted and is actually taught to US Pilots and is listed in the FAA manuals with this definition.
This makes no sense to me, lol. Why would SPS require a Q-Code when it never changes?
Is this a common thing? Is it a US/UK thing? or a US/Rest of the World thing? What do you all think QNE is? Is there not a safety concern with different agencies having different definitions for the same term?