It’s plastered on T-shirts; it tells you which button will start your Prius; it’s even been used on NYC condom wrappers. As far back back as WWII engineers used the binary system to label individual power buttons, toggles and rotary switches: a 1 meant “on,” and a 0 meant off. 


In 1973, the International Electrotechnical Commission vaguely codified a broken circle with a line inside it as “standby power state,” and sticks to that story even now. The Institute of Electrical and Electronics Engineers, however, decided that was too vague, and altered the definition to simply mean power. Hell yeah, IEEE. Way to take a stand. 


via The Secret Histories of Those @#$%ing Computer Symbols