What 𝒃 means
Its bold-italic style distinguishes it from other forms of b. An equation can assign 𝒃 a different role from plain b, italic b, or bold upright b. Some texts use lowercase bold italic for vectors—quantities with size and direction—but the document’s notation decides; this style has no universal definition.
Why is 𝒃 a separate character?
To preserve mathematical distinctions in plain text. Before Unicode, math notation already used different alphabets and type styles to mark quantities. In an 1881 book on vector analysis, J. Willard Gibbs used Greek letters for vectors and English letters for scalars (single-number quantities); E. B. Wilson’s 1901 textbook used bold versus ordinary type for that contrast. A 1999 proposal encoded mathematical alphabets separately so plain-text formulas could retain distinctions usually carried by type styling.
Part of the collection
What it means when someone sends it to you
2 readingsA mathematical variable; its role comes from the writer’s notation.
Don't confuse it with
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Questions people ask
1Can 𝒃 turn into plain b?
It can. NFKC is a Unicode normalization form that folds compatibility-style letters to their base letters; if a text system applies it, 𝒃 becomes plain b. This can erase the distinction between variables in a formula.
More like this
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Collections with 𝒃
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How to type or find 𝒃
- Search it as
- fancy b · decorative text
- Shows up in
- Anything that takes text · its shape is whatever your font draws
𝒃\1D483Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.