Local currency refers to the national currency, which defaults to RMB (because you applied for a credit card in mainland China). In my credit card from HSBC Bank in Taiwan, the local currency refers to the New Taiwan Dollar, and the foreign currency refers to the New Taiwan Dollar. It is the limit of your card swiping overseas. However, no matter which country you have visited and the local currency is settled in, it will be converted into US dollars and withdrawn on the bill on the bill day