2/ For historical reasons many territories have their own ISO codes, despite being part of another country.
An example is 🇵🇷 Puerto Rico (PR) which is part of the 🇺🇸 United States (US)
The process of assigning codes is not quick, it may be some time before a "new" country has an official code. 🇽🇰 Kosovo , recognized by 98 UN member states, does not yet have an official ISO code.
This is why our API returns both ISO codes and a "country_code" field
See: https://opencagedata.com/guides/how-to-determine-the-iso-codes-for-a-location
3/ But today in #geoweirdness let's look at ISO 3166-1 alpha-2 codes that have officially been deleted.
Some countries merged peacefully with others:
The Kingdom of Sikkim (SK) became part of 🇮🇳 India (IN)
https://en.wikipedia.org/wiki/Kingdom_of_Sikkim
The German Democratic Republic (DD) became part of the 🇩🇪 Federal Republic of Germany (DE)
The Gilbert Islands (GE) became part of 🇰🇮 Kiribati (KI) - and the ISO code was later claimed by 🇬🇪 Georgia