Mathematical Bold Small Q

𝐪 is a bold q used as its own mathematical symbol.

Its separate character identity lets the weight keep q distinct inside plain-text formulas. The convention grew over time, not from one inventor. In 1881, mathematician J. Willard Gibbs used small Greek letters for vectors and small Latin letters for scalars, or single-value quantities. E. B. Wilson's 1901 textbook on vector analysis helped popularize bold type for vectors and ordinary type for scalars. Later writers reused that contrast for other distinctions.

Does bold q always mean a vector?

No; it marks a vector only when that text's convention says so.

In physics and applied mathematics, bold lowercase is a common vector style. Across books, notation varies: some use bold type for other mathematical roles, so read the formula's definitions to learn what q represents.

Why does normalization turn bold q into plain q?

NFKC compatibility normalization turns 𝐪 into ordinary q.

Some software uses compatibility normalization, NFKC, to make strings easier to match. It maps 𝐪 to ordinary q; another form, canonical normalization (NFC), keeps the distinction. With font support, the shape follows the selected typeface; without a font that includes 𝐪, an app may show a missing-glyph box or blank.