What ⫑ means
It marks a subset relation that allows equality.
If A ⫑ B, every element of A is also in B; A may equal B.
Is ⫑ the same as ⊆?
Yes: both express the same subset-or-equal relation.
⫑ is the closed-form character; ⊆ is familiar notation. Use the sign specified in the text.
Don't confuse it with
4Worth knowing
- Joseph Gergonne used a C-shaped mark for a set inside another in 1816–17; Ernst Schröder introduced ⊂ and ⊃ for containment and its reverse in 1890. These dates belong to the wider notation, not ⫑.
Questions 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 2AD1, 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 “closed subset or equal to”.
Linux
Ctrl+Shift+UType 2ad1, then Enter or Space.
HTML
⫑CSS
\2AD1LaTeX
A LaTeX symbol reference lists `\csube` for ⫑.
Codes and encoding1 code points
HTML decimal
⫑
HTML hex
⫑
CSS content
content: "\2AD1";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%AB%91
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.