U+1D53B "𝔻" Mathematical Double-Struck Capital D Unicode Character

U+1D53B "𝔻" Mathematical Double-Struck Capital D is a stylized letter D from the double-struck (or blackboard bold) typeface, which is commonly used in mathematics to denote specific number sets or algebraic structures such as the domain of a function or the set of differential operators. It belongs to the Mathematical Alphanumeric Symbols block and is designed for use in formal mathematical notation, where it represents a distinct mathematical object rather than a regular alphabetic letter. This character is typically rendered in a serif, bold, and outlined style to distinguish it from standard text, and it is encoded separately from ordinary uppercase D to ensure consistent display across different platforms and fonts.

General Properties

Code Point	U+1D53B
Version Added	3.1
Name	Mathematical Double-Struck Capital D
Block	Mathematical Alphanumeric Symbols
General Category	Uppercase Letter
Canonical Combining Class	Not Reordered
Bidirectional Class	Left To Right
Decomposition Type	Font
Decomposition Mapping	"D" U+0044 Latin Capital Letter D

Encodings

HTML Decimal Encoding	𝔻
HTML Hex Encoding	𝔻
UTF-8 Encoding	0xF0 0x9D 0x94 0xBB
UTF-16 Encoding	0xD835 0xDD3B
UTF-32 Encoding	0x0001D53B
C/C++/Java Escape	\ud835\udd3b

Unicode Properties

NFC Quick Check	Yes
NFD Quick Check	Yes
Numeric Type	None
Numeric Value	NaN
Line Break	Alphabetic
Uppercase	Yes
Cased	Yes
Changes When NFKC Casefolded	Yes
NFKC Casefold	"d" U+0064 Latin Small Letter D
NFKC Simple Casefold	"d" U+0064 Latin Small Letter D
Script	Common
Script Extensions	Common
Indic Syllabic Category	Other
ID Start	Yes
XID Start	Yes
ID Continue	Yes
XID Continue	Yes
Alphabetic	Yes
Math	Yes
Other Math	Yes
Vertical Orientation	Rotated
Grapheme Base	Yes
Grapheme Cluster Break	Other
Word Break	Alphabetic letter
Sentence Break	Upper