Conference organiser
A registration that keeps up when the places run out
A registration should not have to be rebuilt because reality changes. While there is room the visitor should be able to register. When the places do not go round, the same registration should offer a place on the waiting list instead.
Flowweaver does not have to keep track of how many places there are. It asks the system where that information already lives and fits the next step to the answer. Which means the number of places can change without anybody opening the guide, editing a rule or publishing a new version.
The guide describes what should happen. Your systems account for what changes.