Section 75(2) in The Indian Post Office Rules, 1933
(2)Every parcel tendered for insurance must be packed carefully and substantially, with due regard to the nature of the contents and the length of the journey, and must be sealed with wax or lead, bearing a private mark, in such a way that it cannot be opened without either breaking the seal or leaving obvious traces of violation. Seals must be placed over each joint or loose flap of the covering of a parcel; and, if string be used in packing, a seal must be placed on the ends of the string where they are tied. If a parcel contains gold or silver bullion or coins, it must be placed in a strong case of wood or metal with an outer covering of cloth or stout paper.
