9F3B

Application Reference Currency is the card's own list of one or more currencies its account could reasonably be converted to and evaluated against, per ISO 4217 - it exists specifically to support cards whose risk-management logic needs to compare a transaction in a foreign currency against limits that are meaningfully expressed in the account's own reference currencies, rather than forcing every comparison through the transaction's currency alone. It's related to the Application Reference Currency Exponent (9F43, which states the decimal places for each currency this tag lists) and to the Application Currency Code (9F42, covered earlier, the account's actual operating currency) that 9F3B's list is offered as an alternative or supplement to. Because it can list more than one currency, a terminal or card implementing multi-currency risk checks has to handle 9F3B as a genuine list, not a single value - code that only reads the first entry will silently ignore whatever additional reference currencies the card actually offers. See EMV 4.4 Book 3.