Power Off and Standby Switch Symbols
New Scientist's Feedback column for 21 March 2012 features an item on many devices consuming power when supposedly turned "off". The article suggests having a requirement that "off really means off". But this is already the case. There are two different international standard symbols for a power switch. The one for a true on/off switch has a circle with a vertical stoke in it. This is the IEC 5010 power on-off symbol: the circle represents the number zero and the stroke the number one, the switch representing the binary status of the switch: on or off.