Originally Posted by Starman

Not to quibble on a small thing, but the OP states that HK status means the upgrade is "authorized". This is not quite correct. Status HK simply means "holding confirmed" for _any_ class of service. The correct question to ask would be "Am I now HK in class of service NF [or NC]?" It's an important distinction, because even if the upgrade is NOT preserved correctly, you'll still be HK, however in Y. If you get an agent not experienced enough to understand what the heck you are trying to do, they may well answer "yes" to the question "is my reservation status HK?", because it will be even if not upgraded, but in Y.

It's also a bit dangerous to use the word "authorized" with respect to an upgrade, as this has a special meaning when one is using a sponsored upgrade (pax is not the same as M+ account holder). It's not clear to me whether or not HK truly denotes that the upgrade is correctly "authorized", i.e., that the *UA field shows that an upgrade has been authorized via signature of a bluey at an airport, for example.

The safest interpretation is that HK in NF or NC simply means that one has a confirmed reservation in an upgraded class. Whether or not a sponsored upgrade is correclty "authorized" is a different question.

Sorry if this all seems maniacal, but I've already had ICC agents who don't even know what HK means.