U+1F17E · emoji since 2010
The O button is a red square with a bold letter O, marking blood type O. It means the universal donor and the letter O.
Online it also stands in for the letter O in stylized text, a clean red badge of a letter.
In texting, 🅾️ does not carry a widely used hidden or slang meaning, so you can usually take it at face value. People send it just as it looks, to add a little visual touch or set the mood of a message. Only a handful of emoji have a separate texting code, and 🅾️ is not really one of them.
Its official Unicode name is the O Button (Blood Type) emoji. In everyday chat most people just call it the o button (blood type) emoji or describe what it shows. Copy and paste it from the button at the top of this page.
The 🅾️ leads off a short phrase, and the rest of the words are written in cipher, every letter disguised as another emoji. Tap decipher to reveal the whole line.
Or make your own cipher in the translator.