What 🟖 means
It marks the black stone or group under discussion. In Go diagrams, a triangle marks one target; a square marks another target of the same colour.
The earliest surviving Go diagrams from China’s Southern Song and Yuan periods, dated to the 12th–14th centuries, use black-and-white numbered tags. Later Chinese manuals put written characters inside circles; later commentary uses triangles and squares to point to stones or groups. These are changes in diagram annotation, not Go’s origin.
Technical and niche: a clear fit for Go commentary; alone in ordinary chat, it gives little context.
“Negative” names the inverted form; it does not mean subtraction.
Don't confuse it with
4Questions 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 🟖
🟖\1F7D6Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.