Look up an ISO 4217 currency. Pass code (alphabetic like USD, or 3-digit numeric like 840) for the canonical record, or country to find the currency/currencies a country uses. Returns the alphabetic + numeric code, English name, minor unit (decimal places — e.g. JPY 0, USD 2, BHD 3), and the countries using it. Bundled authoritative ISO 4217 data — the currency-code + decimal-places ground truth an LLM gets wrong on less-common currencies.