||Required for MPS shipments. Total number of packages in the shipment.
||Required if PackageCount is greater than 1. The sequence number determines the master package and is important when shipment level information is added for that package. The shipment level information added to a master package applies to all packages in the shipment.
||Required. The MasterTrackingID element is returned with the first package reply. This element contains both the MasterTrackingNumber and the FormID elements. The MasterTrackingID element must be added to each subsequent ship request for all other packages in the MPS shipment.
||Valid values are: