When we have a new reservation, say for New Year's Eve, it's common to manually adjust rates and/or LOS requirements around the booking. But, if that reservation cancels, all of those changes need to be reverted, and they need to be reverted quickly to prevent someone from booking similar dates at altered requirements (rate or LOS). Having a trigger, like a specific reservation number cancelling, that automatically undoes the changes would solve this perfectly. (User would probably have to make all the needed adjustments under 1 "save" so that they can all be undone under one "undo", but aside from that requirement, this should work.