Section 18. If any dutiable goods are exported by sea to any foreign port before the return in respect of them h

18. If any dutiable goods are exported by sea to any foreign port before the return in respect of them has been delivered to the Collector under section 8, the owner of the mill in which they were produced may apply in writing to the Customs Collector at the port of shipment, who, on being satisfied that such goods have actually been shipped for export, shall issue a certificate stating the quantity and particulars of such goods and that they have actually been so shipped. When certificate granted, goods to be exempt from duty. 18. Grant of certificate when dutiable goods are to be exported to foreign port.