This is the CodeSystem that contains all the codes in ISO 3166-1 Codes for the representation of names of countries and their subdivisions — Part 1: Country code (urn:iso:std:iso:3166) and ISO 3166-1 Codes for the representation of names of countries and their subdivisions — Part 1: Country code (urn:iso:std:iso:3166). E.g. what you have to deal with if you get resources containing codes in either of them