Thanks all for the info here. Now I finally understand my receipt for my hotel bill, and why the exchange rate that they (Westin front desk) insisted was correct seemed fishy. It was literally the only time I used my CC for anything in China on my recent trip, and fortunately for a relatively small hotel bill. 'A good way to learn the lesson (4.25% extra skimmed off by BoC). I'll be much more prepared and knowledgable next time around. It was a Bank of China charge receipt and looks almost exactly like what's described in this thread. The hotel employees certainly did not offer any choices, and simply insisted that they were using the correct exchange rate when I questioned that the amount seemed high.