What ㌈ means
It means acre, written in Japanese as エーカー. Katakana is the Japanese syllabary used for this borrowed word. A Japanese dictionary's earliest cited example dates to 1877; that date belongs to the word, not this boxed form.
Four kana fit inside one square cell, the width of a typical East Asian character. This is one of the squared Katakana forms inherited from older Japanese character sets; horizontal and vertical text can arrange the kana differently.
Don't confuse it with
1エーカー
㌈ vs エーカー: one is a single boxed character; the other is the ordinary four-kana spelling.
Questions people ask
1Why does ㌈ 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 ㌈
Windows (Word)
Alt+XType 3308, then Alt+X to get ㌈.
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 “square eekaa”.
Linux
Ctrl+Shift+UType 3308, then Enter or Space.
HTML
㌈CSS
\3308Plain word
Type エーカー as four ordinary kana.
How to type ㌈
Use a system character picker; entering エーカー gives the ordinary four-kana spelling.
Codes and encoding1 code points
HTML decimal
㌈
HTML hex
㌈
CSS content
content: "\3308";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E3%8C%88
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.