Let us now see what does P.Cost means. P.Cost is known as Provisional Cost in the shipment.
All cost charges which are entered in the shipment costing sheet are considered under P.Cost.
Either the charge may be posted or kept unposted does not matter in the shipment. All cost charges available in the shipment are available as provisional charge and they will be able to preview in the reports as P.Cost.
Refer below screenshot for shipment charges and report screen for further understanding. There are three cost charges present and the sum of three charges is available to preview as P.Cost in the reports.