Having worked software development in a bank before I know how important it is to work with proper data structures and enumerations.
I had a program I needed to write where I had to utilize ISO country codes and there was a lot of interoperability work that needed to be done. So I tried looking for some basic library that had the standard ISO-3166 country codes. Couldn’t find any. I really just needed something I could look up a country code quickly and get its description. Like saving “SLV” or “222” as a key in a database for El Salvador’s currency. Then I can retrieve it and do a look up on a table to get the country name. Or even vice-versa.