What 🨀 means
It belongs to neither side; either side may move and capture it.
Fairy chess adds new pieces or rules to chess problems; the problem's rules set how this king moves.
How did neutral chess notation develop?
Older diagrams turned white-piece symbols to show neutral pieces.
Older problem publications turned white-piece symbols to represent neutral pieces; a 2017 proposal describes split forms as clearer. Printers also turned small metal blocks bearing chess-piece shapes to depict unusual pieces. Chess puzzles reach back to shatranj, an earlier chess form, where composed positions called mansūbāt were used.
Don't confuse it with
1Combination ideas
1Questions people ask
1Why does 🨀 show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type 🨀
🨀\1FA00Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.

