What 𝚳 means
The equation defines Mu’s role; bold marks its mathematical form.
Mu is a letter in the Greek alphabet; its ordinary capital form is Μ. Mathematical bold can distinguish it from a plain or differently styled symbol, and the equation’s definitions reveal its role.
The 1999 Unicode proposal records scientific publishers already using distinct Latin and Greek letter styles. It sought separate characters so web-based plain text could preserve those distinctions, extending a smaller set of letter-shaped math symbols already encoded.
Why can normalization turn 𝚳 into Μ?
NFKC or NFKD can fold it to ordinary Greek capital Mu.
NFKC and NFKD are Unicode normalization forms that fold compatibility variants. Applying either can map 𝚳 to Μ and discard the bold distinction the formula may depend on.
Bold carries mathematical meaning; in browsers and print views in 2026, math fonts could omit it or draw it differently.
Part of the collection
Don't confuse it with
1Related characters
1
Questions people ask
1Why does 𝚳 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.
More like this
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How to type or find 𝚳
- Search it as
- bold mu · greek mu symbol · math mu · bold greek mu · unicode mu
- Shows up in
- Anything that takes text · its shape is whatever your font draws
𝚳\1D6B3Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.