Export obligation verification under duty exemption schemes requires random checks, acceptance of discharge certificates absent intelligence, and quarterly reporting. Customs must verify export obligations under EPCG, Advance Authorization, DFIA and Chapter 3 duty credit scrips through submission and random checking of installation certificates and shipping bills, accept Export Obligation Discharge Certificates absent specific intelligence of misuse, and report quarterly on discrepancies; where obligations are unmet EPCG requires payment of proportionate duty with interest and timely action to safeguard revenue and facilitate bond/bank guarantee redemption.