What 𝑜 means
It is a lowercase mathematical italic o used as a variable.
In 1591, French mathematician François Viète used vowels, including capital O, for unknown quantities—values not yet known. In 1637, French mathematician René Descartes helped establish lowercase italic letters for unknowns. A 1999 proposal for Unicode, the character-encoding standard, argued that mathematical styles can distinguish different objects in a formula, so plain text should preserve those distinctions.
Why does 𝑜 turn into o?
Compatibility normalization can turn it into ordinary o.
Unicode's NFKC compatibility normalization maps 𝑜 to plain Latin o. Software that applies it can erase the mathematical distinction; Unicode guidance says not to use NFKC on mathematical text. The font supplies the drawn shape, so the exact slant and design can vary.
Technical and mathematical; lowercase italic letters conventionally denote variables in equations.
For ordinary prose, italicize a plain o; this character belongs to mathematical notation.
Part of the collection
Don't confuse it with
1
Questions people ask
1Why does 𝑜 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.
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How to type or find 𝑜
- Search it as
- italic o · math italic o · unicode italic o · fancy o
- Shows up in
- Anything that takes text · its shape is whatever your font draws
𝑜\1D45C𝑜 as a hexadecimal numeric character reference to produce 𝑜.Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.