For power off button they reused Heavy Circle.

From the article:

> "So, ⭘ is our ½ character "

Oh the irony of this comment not working. :)

Works for me :P

I can't tell if the rendering I see is correct or not. Can you describe the correct rendering and some incorrect yet probable one(s)?

It is a "heavy circle".

This page may help: https://decodeunicode.org/en/u+02B58

The symbol was already present, but it was given new documented semantic content ("meaning"). Previously it was just a circle, now it's also the symbol for "power off".

>You can't say its only a half

The character is only half a character.

There, I just did.