What 𝓍 means
The equation defines it; style distinguishes it.
𝓍 is Latin x in calligraphic form. In one equation, script and plain letters can name different variables.
A paper René Descartes prepared before 1629 uses x for an unknown; his 1637 book La Géométrie uses x, y, and z that way. By the Unicode proposal in 1999, script letters were already used in scientific publications; separate characters let plain text preserve their mathematical distinctions.
Don't confuse it with
4Questions people ask
1Why can 𝓍 turn into x or look different?
Compatibility normalization (NFKC or NFKD) can fold it to plain x. Mathematical fonts also draw script letters differently, so its shape may vary while the character stays the same.
How to type 𝓍
Windows (Word)
Alt+XType 1D4CD, then Alt+X to get 𝓍.
Windows
Win+Rrun charmap for the full table, or use the emoji picker's Ω symbols tab (Win + .).
macOS
Control+Command+SpaceOpen the character viewer and search “mathematical script small x”.
Linux
Ctrl+Shift+UType 1d4cd, then Enter or Space.
HTML
𝓍CSS
\1D4CDCodes and encoding1 code points
HTML decimal
𝓍
HTML hex
𝓍
CSS content
content: "\1D4CD";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%F0%9D%93%8D
1
On screen
1
Code points
2
JS .length
4
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.