What ₊ means
That lower placement is part of the character, not just a font effect. In formulas, it marks a plus in a subscript position.
In medieval manuscripts, high and low signs served as shorthand; formulas later used subscripts to label quantities. A + mark appears as an abbreviation for Latin et (“and”) in a manuscript dated 1417; printed + marked business surpluses and deficits in 1489. Those dates concern ordinary +. Unicode retains ₊ for conversion with older character sets.
Don't confuse it with
2Questions 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 208A, 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 plus sign”.
Linux
Ctrl+Shift+UType 208a, then Enter or Space.
HTML
₊CSS
\208APowerPoint
Choose Insert > Symbol, normal text, and the Superscripts and Subscripts subset. Ctrl+= styles text low but may not insert ₊.
Codes and encoding1 code points
HTML decimal
₊
HTML hex
₊
CSS content
content: "\208A";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%82%8A
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.