Removal of excisable goods for testing permits duty free outward movement and conditional return or clearance subject to specified conditions. Enables manufacturers, by special order and subject to conditions specified by the Principal Commissioner or Commissioner, to remove excisable goods duty free from the factory for tests or non manufacturing processes and thereafter either return them duty free for subsequent clearance or have them removed for domestic clearance on payment of duty or for export without duty; expressly excludes prototypes sent out for trial or development testing.