*Trigger if not group = the action only triggers on bookings that are not part of a booking group. The Invoice Balance trigger uses the booking balance.
*Trigger all if group = the action will trigger on all bookings in a group but only on group bookings. The Invoice Balance trigger uses the booking group balance.
*Trigger only master if group = the action will only trigger on the master booking and only if it is a group booking. The Invoice Balance trigger uses the group balance.
*Trigger all on master if group = the action will apply to all bookings in a group when the master booking meets the trigger condition and only on group bookings. The Invoice Balance trigger uses the booking group balance.