The linked exchange rate is highly consistent with the issuance mechanism of the Hong Kong dollar. There is no central bank in Hong Kong, and it is one of the few places in the world where commercial banks issue bank notes. Hong Kong dollars are issued by the Exchange Fund. The Exchange Fund is the only place for Hong Kong's foreign exchange reserves, so it is a reserve issued by Hong Kong dollars. When issuing banknotes, note-issuing banks must pay a deposit of 100% of foreign exchange assets to the Exchange Fund in exchange for an interest-free "debt certificate" as the basis for issuing banknotes. The assets convertible into bonds are silver, silver dollar, pound, US dollar and Hong Kong dollar. After the implementation of the linked exchange rate system, it is stipulated that it must be exchanged in US dollars. In the history of Hong Kong, no matter what kind of assets are converted into bonds, they must be in full. This is a major feature of the Hong Kong dollar issuance mechanism, and the linked exchange rate system is still used today.