The line symbol means “power on” and the circle symbol means “power off”. The presence of both (I/O) on a push button means the switch toggles the power.
If you must have a non language based symbol, I think + for on and – for off is much easier to remember and would work much better. I can't imagine anyone of ...
An easy way to remember what the circle and line mean is to think of it as a 1 and 0. Recall your computer science, logic, electrical engineering, whatever ...
⭘. IEC 60417-5008, the power-off symbol (circle) on a button or toggle, indicates that using the control will disconnect power to the device. (0 or ◯ means off.).
On/Off Markings To meet the standard IEC 60417, the symbol for ON is “I” (a straight line) and the symbol for OFF is “O” (a circle) . It is important to check the appropriate equipment standard for instructions regarding the position of “on” as som