A split shipment is when a single order containing multiple products is sent in separate shipments. This is due to space and weight restrictions on the aircraft. If a shipment is split, and part of the shipment moves onto another aircraft then that information needs to be updated in ACE Air by sending the boarded quantity and weight along with Part-Arrival Reference Number (PARN) for that shipment. A PARN is usually indicated as A,B,C, etc.