This is not a duplicate question, I have a very rare problem.
More than a year ago, the ISO currency code "Belarusian Ruble" changed. Previously it was "BYR", and now "BYN". Since then, there have been many updates to Magento, but the list of currencies and their codes has not changed.
Using the settings in the admin panel (System > Manage Currency > Symbols ), I can change the display of the currency ISO code at frontend, but inside in system it still wrong.
So I can not use payment solutions in my country, auto-renewal of exchange rates and many other things.
Please explain how to fix the wrong currency code in the Magento core?
Magento version CE 220.127.116.11