1) NEMA connectors cannot signal how much voltage/power they can handle though. If they could, there would be more pressure to use a single connector 2) You ab

1) NEMA connectors cannot signal how much voltage/power they can handle though. If they could, there would be more pressure to use a single connector 2) You absolutely can plug the wrong IEC13/14 cable in to incompatible devices, or pass more capacity than it's rated for. For example, I've seen equipment with IEC14 sockets that only takes 120V (not SMPS), nothing stopping you from plugging in a UK240xIEC13 and letting some angry pixies loose. Is that IEC compliant usage? Who knows, but it's convenient so manufacturers do it anyways.