Export under Central Excise seal: invoice requires exporter declaration and sequential official certifications for shipment to Bhutan. Invoice form for goods liable to Central Excise Duty transmitted under the Central Excise seal for export to Bhutan, requiring exporter declaration of non diversion and detailed consignment particulars (marks, description with tariff classification, weight, value, duty particulars and documentary references). The form mandates sequential official certifications: identification and sealing by a Central Excise Officer, running serial number by the Border Examiner, certification of passage by the Indian Border Customs Officer, and receipt/accounting certification by the Bhutanese Customs Officer with official seal.