Honestly, not all of us are of English origin! Maybe not even you, I don't know! So, I apologize for inaccuracy in my writing (if any!). If you compare my definition as I was taught many years ago and that one of ICAO, what do you get?
Same **** different wrap! One gives QNH, another one elevation! Or other way round!
ATC Creep
It was not my intention to criticise the accuracy of your writing in English, which is excellent. But in the context of the discussion about temperature errors, there is a significant difference between your definition and ICAO's. The QNH is
measured at the airport, not measured at sea level and "corrected". That was the only point I was making.