The opt-in model is the concept that is also applied to the Euro or Schengen Area.
Europe | United States Army Air Forces | Israel Defense Forces | Eastern Europe | Canadian Forces | Central Europe | British Armed Forces | United States Armed Forces | Council of Europe | Organization for Security and Co-operation in Europe | Western Europe | American Forces Network | United Nations Economic Commission for Europe | Europe 1 | Latin Europe | Victory in Europe Day | American Expeditionary Forces | United States Air Forces in Europe | Canadian Forces Decoration | Telefónica Europe | MTV Europe | Miss Europe | Europe (band) | Singapore Armed Forces | Radio Free Europe | Galicia (Eastern Europe) | College of Europe | Soviet Air Forces | Northern Europe | NFL Europe |