Box 4 must always be completed for secure cargo.The appropriate code for the security status of the consignment must be ticked.One of the following codes is used;SHR Secure for passenger, all-cargo and all-mail aircraft in accordance with high riskrequirements.SPX Secure for passenger, all-cargo and all-mail aircraft.SCO Secure for all-cargo and all-mail aircraft only. This code may not be used for cargooriginating within the UK.