When a 25Live user is creating an event and assigns a resource, a pending reservation (assignment) is created to hold that resource while the user finishes creating the event. This is done to prevent conflicts that would occur if another user tried to schedule the same resource at the same time. If the user's browser crashes during the event creation process, the pending reservations are never discharged. The Administration Utility lets you view and remove these pending resource reservations.
If you’re unsure whether or not a reservation is still active, don’t remove it.