Permission for entry of duty paid goods for rejection, servicing or non similar repacking, subject to revenue safeguards. Chief Commissioners are authorised to permit entry or retention of duty paid goods in factories or warehouses where goods are rejected by the buyer, require after sale servicing, or need packing/re packing provided such goods are not similar to those manufactured in the factory; permissions must incorporate revenue safeguards against MODVAT misuse and evasion, and Chief Commissioners must prescribe procedures and documents for entry and clearance, report on the provision's working to the Board, and issue trade notices.