US Bonded warehouses, CFS, ECCF.

What is Freight Status Notification (FSN)?
For a US warehouse to receive status notification messages on air shipments going into their facility on release or transfer of the cargo. The warehouse cannot release the cargo out of the facility if there is a hold or customs inspection message on the shipment.

What is Freight Status Query (FSQ)?
Freight Status query is a type of message the warehouse can send to CBP to check for status of an air waybill (MAWB, HAWB). After a FSQ message is sent to CBP, it will return back with a FSC message indicating the info.