When you make your first transaction in a country you are visiting you get a notification welcoming you to the country, exchange rate and cash withdrawal fees etc.
In there is says that you’re charged a 3% fee after £200 worth of cash withdrawals. It would be good to update this to somehow include that the mastercard exchange rate is used, as the 3% fee is higher on paper than my banks fee. However it is actually lower when you take into account the bad exchange rate. This then makes it a more positive message.