It should never be possible to place both a hold and a booking on a single item but currently bookings will correctly hide itself if not enabled via the itemtype as an option but we cannot do this for holds. For example, we have orchestral sets we hire out that should only be bookable. We've disabled to 0 for number of holds via the circ rules but the holds/reservations tab and button will still show. This is confusing for staff. Ideally, there would be a mirrored option by item type to disable holds to correct this.