This is simply about what the United Nations (not you, not me) calls a member state. For example "Germany" is the official name of that sovereign entity as far

This is simply about what the United Nations (not you, not me) calls a member state. For example "Germany" is the official name of that sovereign entity as far as UN is concerned. Previously there were 2 of them, one officially named as "The Federal Republic of Germany", and the other "German Democratic Republic". Also see: "On 17 May 2016 the Permanent Mission of the Czech Republic to the United Nations informed the UN that the short name to be used for the country is Czechia." https://www.un.org/en/about-us/member-states/czechoslovakia https://www.un.org/en/about-us/member-states/czechoslovakia