U+2146 "ⅆ" Double-Struck Italic Small D Unicode Character

U+2146 "ⅆ" Double-Struck Italic Small D is a specialized typographic symbol used primarily in mathematical and scientific notation to represent a differential d in a clear, stylized manner, such as when denoting an infinitesimal change in calculus or a differential operator. It belongs to the Letterlike Symbols block and is designed to distinguish the variable or operator from other italic letters, often appearing in contexts like integrals or derivatives where precision is key. This character is part of a set of double-struck italic letters that mimic the appearance of blackboard bold typefaces, yet retain an italic slant, making it a distinct tool for professional typesetting in fields like physics and engineering.

General Properties

Code Point	U+2146
Version Added	3.2
Name	Double-Struck Italic Small D
Block	Letterlike Symbols
General Category	Lowercase Letter
Canonical Combining Class	Not Reordered
Bidirectional Class	Left To Right
Decomposition Type	Font
Decomposition Mapping	"d" U+0064 Latin Small Letter D

Encodings

HTML Decimal Encoding	ⅆ
HTML Hex Encoding	ⅆ
UTF-8 Encoding	0xE2 0x85 0x86
UTF-16 Encoding	0x2146
UTF-32 Encoding	0x00002146
C/C++/Java Escape	\u2146

Unicode Properties

NFC Quick Check	Yes
NFD Quick Check	Yes
Numeric Type	None
Numeric Value	NaN
Line Break	Alphabetic
Lowercase	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	Upright
Grapheme Base	Yes
Grapheme Cluster Break	Other
Word Break	Alphabetic letter
Sentence Break	Lower