For Corp to give a hotel a "waiver" for the guarantee, they have to show the hotel as being contracted by someone (or a group) for all their rooms or some "event" has to be involved that will in effect contract all their rooms (i.e Superbowl, etc.). It doesn't have to be a "big" event, but if someone contracts for ALL the rooms (and it could be for a tiddlywinks group, a really big family vacation, whatever), but if they have ALL the rooms contractually, then the hotel is basically not a "hotel" for those nights. They have to show Marriott the contract and only then will they be given a waiver.

This is actually one of the benefits I like how Marriott does it better than the other hotel chains. The hotel doesn't directly control this benefit. If they don't get the waiver, then the online tool will allow a Plat to get a room, the hotel can't stop it. The only "control" they have is to apply for that "waiver" from corp. And corp will not give it to them just because they are "full".