找到了1897/12/24y邮票章程 b 16 Union stamps are not on sale to the public. The public must be induced to buy Chinese stamps and use them to frank outward international mail matter. Where domestic mail matter is concerned the stamps should as usual be affixed on the face; but where international mail matter, i.e. mail destined for foreign countries, is concerned the Chinese stamps should be affixed on the back of the of the articles so as to leave the front free for the Union stamps and the duty of affixing Union stamps of a value equal to the Chinese stamps devolves on the Postal Officer.