Regulations Governing the Handling of Mail Article 41
With regard to banknotes, coins, gold or silver bullion, gold or sliver utensils, precious stones and jewelry, only those permitted by law can be mailed.
中文原文 郵件處理規則第41條
郵寄法定紙幣、硬幣、金銀條塊、金銀器具、寶石珍飾等貴重物品，以法令許可者為限。