Duty exemption for Advance Licence imports subject to conditions including bond, specified certificate, and discharge of export obligation. Materials imported against an Advance Licence are exempt from specified customs duties provided imports are covered by a Duty Exemption Entitlement Certificate, the licence and certificate are produced at clearance, and export obligation in respect of specified resultant products is discharged within the prescribed period. The importer must execute a bond with security to secure payment of duties with interest where conditions are not met; bonds are unnecessary after full discharge. Re-export of defective goods within three years and administrative limits on interest in default cases are prescribed.