Three symbols were adopted for power, including the familiar one, the aforementioned enclosed circle, and the waning crescent Moon for sleep. The IEEE standardized these in IEEE Standard 1621.

Here’s what the symbol means and where it came from. The iconic power symbol, explained The power symbol, which can still be seen on nearly all modern PCs and laptops, originated in the 1950s.

An electric power button symbol inched past other entries to win New York’s condom wrapper design contest, the city said Tuesday. The winning design shows the familiar “on” symbol… ...

The original Xbox’s disc eject button was the most important button on the console — even more so than the power button. And Microsoft’s emphasis on the disc drive reflects an ongoing shift ...

While the power symbol made it into Unicode in 2015, it's been around for much longer. The goal in moving it to Unicode was to add a crucial symbol used around the world by the masses.