What ⫾ means
It marks a choice among guarded commands. Each pairs a condition with an action; only those with true conditions qualify, and if several do, the choice stays open.
Dijkstra’s 1973 report says a heavy bar, ▯, replaced commas; it was inspired by Peter Naur’s bar between alternatives in grammar rules.
Don't confuse it with
1Worth knowing
- A 2013 Unicode font review records designs distinguishing the pair by height or stroke weight.
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 2AFE, 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 “white vertical bar”.
Linux
Ctrl+Shift+UType 2afe, then Enter or Space.
HTML
⫾CSS
\2AFEWindows
In Microsoft Office, type 2AFE, then press Alt+X.
Linux
Press Ctrl+Shift+U, enter 2afe, then Enter.
TeX
With unicode-math and a supporting font, use \talloblong.
Codes and encoding1 code points
HTML decimal
⫾
HTML hex
⫾
CSS content
content: "\2AFE";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%AB%BE
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.