What are Port and Sub Location Codes?

What are Port and Sub Location Codes?

Port of Destination
This is a CBSA port code where release/acquittal will take place.
Port  of Destination Sub Location Code
The sub-location/warehouse related to the Port of Destination/Exit where the shipment will be released/ acquitted.
Port of Discharge
Office code of CBSA-designated seaport, airport, freight terminal, rail station, or other CBSA-approved location at which goods are unloaded, if different than the Port of Destination.
Port of Discharge Sub Location Code
The sub-location/warehouse where the shipment is to be warehoused.