The ones returned by /refb.merchant.v1.MarketService/ListMarkets / ListMarkets() and by /refb.merchant.v1.CurrencyService/ListCurrencies / ListCurrencies(). For currencies: there are currently 5 available currencies you can manage your prices in (EUR, GBP, DKK, SEK, PLN). But we might add more in the future, that is why we implemented an API method instead of a predefined enum.