Meaning
A square holding a mix of symbols, typically things like an ampersand, a percent sign and a music note, the label for typing special characters. It stands for symbols and punctuation beyond letters and numbers.
People use it when talking about special characters, password rules or fancy symbols for usernames and bios: “Password needs at least one 🔣, of course” It also suits grumbles about formatting and copy-paste trouble. Compare 🔤 for letters and 🔢 for numbers.