Originally Posted by
mnttech
WOW....
From the US AIM pilot controller glossary
I know, not in the USA, but I can find that document
It is a standard CPDLC message look up the ICAO 'GOLD' document.
It is normal practice in many oceanic centers to precede any request for a level change with MAINTAIN LEVEL ###; followed by any further instruction on level change exactly because of the problem in this case.