Code point
U+23F9
Glyph appearance depends on your fonts.
U+23F9
SoU+23F9 BLACK SQUARE FOR STOP is a Unicode 16.0.0 character in the Other Symbol category. It belongs to the Miscellaneous Technical block.
Choose the representation you need, then copy its value.
U+23F9
9209
⏹
⏹
E2 8F B9
23F9
000023F9
%E2%8F%B9
\u23F9
\u23F9
\u23F9
\23F9