What ␓ means
␓ is the visible mark for DC3, an invisible control code.
ASCII, an early computer text standard, was first issued in 1963. On a Model 33 Teletype, DC3 could stop its attached paper-tape reader.
A 1992 terminal protocol described Ctrl-S/XOFF pausing output and Ctrl-Q/XON resuming it.
Technical and archival; it marks control-code or terminal context.
Typing ␓ does not trigger DC3.
What it means when someone sends it to you
2 readings␓ in text
A printed label, with no control action.
Ctrl-S in a terminal
May pause output; the terminal can intercept XOFF before a program receives it.
Don't confuse it with
4Combination ideas
1Pause output, then resume it.
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 2413, 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 “symbol for device control three”.
Linux
Ctrl+Shift+UType 2413, then Enter or Space.
HTML
␓CSS
\2413Terminal
With software flow control enabled, Ctrl-S invokes XOFF; Ctrl-Q resumes output.
Codes and encoding1 code points
HTML decimal
␓
HTML hex
␓
CSS content
content: "\2413";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%90%93
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.