Clarifying some "countries" in location groups

Greetings,

In location groups, there are a few “countries” listed that don’t correspond to actual countries (or ISO 3166-1). Hoping someone can clarify how a few country codes are defined.

  • Europe (EU): Does this represent all of the European Union, the European continent, or a miscellaneous type that only includes other European IPs not assigned to specific countries? The Wikipedia article on the standards mentions EU as being reserved, but doesn’t go into detail.

  • France, metropolitan (FX): According to ISO 3166-3, this code has been deprecated and merged into France proper. In the location database, do France and France, metropolitan overlap? Why is this code being used?

  • More generally, do some of these country codes represent a superset of several others, or are all of the country codes mutually exclusive?

I realize that the data for the location database originates elsewhere, and that probably has something to with the country classifications being used in IPFire.

Thanks for your insights.
Denis