What 𝕕 means
Read it as a separate math letter whose role the author defines. The doubled strokes began as a chalkboard workaround for making symbols look bold without filling them in. Printed mathematics later used the style especially for capitals naming number sets. By 1985, the American Mathematical Society's first general release of mathematical symbol fonts included blackboard-bold capitals; lowercase 𝕕 extends the style beyond familiar set labels.
Read it as a mathematical symbol, not decoration; its formula supplies the meaning.
Unicode compatibility normalization, a text-cleanup form, can fold 𝕕 to plain d.
Part of the collection
Don't confuse it with
4
Latin Small Letter D
Plain Latin small d. The double-struck letter is a styled copy with its own code point, so plain-d search misses it.
Cyrillic Small Letter Komi De
Cyrillic-script Komi De, a letter that looks like d. Used to spoof Latin words in web addresses and names.
ⅆ
Double-Struck Italic Small D
Double-struck italic small d, a letterlike symbol. Looks like d in most fonts; a separate code point.
ｄ
Fullwidth Latin Small Letter D
Same letter at CJK width; wider and upright, but easy to paste by mistake.
More like this
11
How to type or find 𝕕
- Search it as
- blackboard bold d · double struck d · mathbb d
- Shows up in
- Anything that takes text · its shape is whatever your font draws
Windows (Word)
Windows
macOS
HTML
𝕕CSS
\1D555Codes and encoding1 code points
HTML decimal
𝕕
HTML hex
𝕕
CSS content
content: "\1D555";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%F0%9D%95%95
1
On screen
1
Code points
2
JS .length
4
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.