Maybe not the symbol, but the article artificially constraining itself to 'M' seems a bit suspect to me. In my country the symbol for the metro isn't even M [1]

Maybe not the symbol, but the article artificially constraining itself to 'M' seems a bit suspect to me. In my country the symbol for the metro isn't even M [1] [1] https://upload.wikimedia.org/wikipedia/commons/7/7d/Singapore_Public_Transport.jpg https://upload.wikimedia.org/wikipedia/commons/7/7d/Singapor...