What ⁗ means
The surrounding formula defines its exact meaning. In math, f⁗(x) can denote the fourth derivative of f(x); another formula may use the mark for a different fourth-level label.
In older astronomy, a “third” was 1/60 of an arcsecond; ⁗ marked a “fourth,” 1/60 of a third. Modern astronomy uses decimal fractions.
Technical punctuation for math and specialist reference.
If ⁗ appears as a box, the font or fallback has no glyph for it.
Don't confuse it with
2Questions people ask
1Why does ⁗ 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.
How to type ⁗
Windows (Word)
Alt+XType 2057, then Alt+X to get ⁗.
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 “quadruple prime”.
Linux
Ctrl+Shift+UType 2057, then Enter or Space.
HTML
⁗CSS
\2057Linux Unicode input
Press Ctrl+Shift+U, type 2057, then Enter or Space (as of 2025).
Word equation
In a Word equation with Unicode conversion mode on, type `\qprime` or `\quadprime`, then Space (as of 2026).
Codes and encoding1 code points
HTML decimal
⁗
HTML hex
⁗
CSS content
content: "\2057";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%81%97
1
On screen
1
Code points
1
JS .length
3
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.