One method for resolving this situation is taken in Poland, exactly where CEE 7/5 sockets are typically installed in pairs, the higher (upside-down) one having the "French" polarity as well as the reduced a single possessing the "Czech" polarity, so that the person can pick out what to plug wherever. https://typesofmicrophonesandthei60379.qodsblog.com/29390197/the-fact-about-type-of-electrical-plugs-in-tanzania-that-no-one-is-suggesting