Meaning
The kanji 禁 on a square button, usually red, meaning forbidden or prohibited in Japanese. It is the character you see on no-smoking and no-entry signs.
People use it for rules, bans and off-limits topics, often with a humorous twist: “Talking about work at dinner 🈲” It looks stricter and more official than a plain ❌. For a no sign that everyone understands instantly, 🚫 is clearer.