Interresting warning messages.
I unwrapped a HP ProCurve switched recently and this sticker was placed on the power socket:
It comes with a normal IEC C14 power connector. It accept voltages from 100-127 V – 200-240V 50 and 60Hz. I have _no_ idea why anybody that buys a switch like this would needs instructions from a user-guide for plugging in this connector.