What ⦸ means
Check the equation's own key for its exact operation.
Unicode’s math guide dated 2025-10-02 lists ⊘ and ⦸ among the slash and reverse-slash symbols. A math-property table dated 2017-06-01 records obsol as an entity name but leaves its ISO entity-set field blank; that label alone does not establish an original use.
Don't confuse it with
1Questions 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 29B8, 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 “circled reverse solidus”.
Linux
Ctrl+Shift+UType 29b8, then Enter or Space.
HTML
⦸CSS
\29B8LaTeX
With `stmaryrd` loaded, the LaTeX command `\obslash` produces it; the `hyperref` reference documents this mapping as of 2026-06-17.
Codes and encoding1 code points
HTML decimal
⦸
HTML hex
⦸
CSS content
content: "\29B8";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%A6%B8
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.