Customs duty exemption for Advance Licence imports conditioned on fulfilment and proof of export obligations and bond security. Materials imported under an Advance Licence and covered by a Quantity Based Duty Exemption Entitlement Certificate are exempt from customs and specified additional duty subject to conditions: imports must be covered by the certificate in respect of value, quantity and specifications; the licence and certificate must be produced at clearance; a bond with security must be executed to secure duty and interest where conditions are not met (unless export obligation is discharged); export obligations must be fulfilled within the certificate period or extensions and evidenced to customs; and exempted materials are restricted to use for specified export products and replenishment only.