U+1D564 "𝕤" Mathematical Double-Struck Small S Unicode Character

U+1D564 "𝕤" Mathematical Double-Struck Small S is a typographical glyph from the Mathematical Alphanumeric Symbols block, designed for use in mathematical and scientific notation where a distinct, blackboard bold style is required. This character is specifically the lowercase letter "s" rendered with double strokes, often employed to represent sets, number systems, or special algebraic structures in academic writing. It ensures clear differentiation from standard alphabetic characters, avoiding confusion in complex formulas. As part of Unicode's comprehensive mathematical encoding, it supports precise semantic representation across digital formats, though its use has declined with the rise of LaTeX and other specialized markup systems.

General Properties

Code Point	U+1D564
Version Added	3.1
Name	Mathematical Double-Struck Small S
Block	Mathematical Alphanumeric Symbols
General Category	Lowercase Letter
Canonical Combining Class	Not Reordered
Bidirectional Class	Left To Right
Decomposition Type	Font
Decomposition Mapping	"s" U+0073 Latin Small Letter S

Encodings

HTML Decimal Encoding	𝕤
HTML Hex Encoding	𝕤
UTF-8 Encoding	0xF0 0x9D 0x95 0xA4
UTF-16 Encoding	0xD835 0xDD64
UTF-32 Encoding	0x0001D564
C/C++/Java Escape	\ud835\udd64

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	"s" U+0073 Latin Small Letter S
NFKC Simple Casefold	"s" U+0073 Latin Small Letter S
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	Lower