What ₍ means
It opens a parenthetical group set below the line. MARC-8, a character set for library records, assigns it an entry; a 2007 MARC 21 table maps that entry to this character. Its job is punctuation; the surrounding notation supplies the meaning.
Can it format a whole expression?
No; this glyph only positions itself low. Use your editor's subscript style for longer text. Compatibility normalization—a text-processing step that folds alternate forms—can turn it into ordinary (, losing the lowered position.
Don't confuse it with
4Questions 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 208D, 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 “subscript left parenthesis”.
Linux
Ctrl+Shift+UType 208d, then Enter or Space.
HTML
₍CSS
\208DCodes and encoding1 code points
HTML decimal
₍
HTML hex
₍
CSS content
content: "\208D";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%82%8D
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.