... or look up the revision status, e.g. amendments incorporated, in the up to date
Catalogue of ICAO Publications, compare those with the online found ICAO Doc. and decide if you can trust this document or not.
Well that's how I do it
As it's for my private pleasure and not official. ICAO Documents are more on the expensive side and just to look something up the Danish site is a good source and most of the time up to date.