U+1D566 "𝕦" Mathematical Double-Struck Small U Unicode Character

U+1D566 "𝕦" Mathematical Double-Struck Small U is a typographic symbol belonging to the Mathematical Alphanumeric Symbols block, designed for use in mathematical and scientific notation to represent a variable in a bold, blackboard bold style. This double-struck form, characterized by its extra vertical stem strokes, is commonly employed in fields like set theory, linear algebra, and number theory to denote specific sets or elements, such as a vector or a member of a universal set. It is distinct from the standard Latin lowercase "u" to ensure clarity in complex equations, and its inclusion in Unicode allows for consistent digital representation across different platforms and fonts.

General Properties

Code Point	U+1D566
Version Added	3.1
Name	Mathematical Double-Struck Small U
Block	Mathematical Alphanumeric Symbols
General Category	Lowercase Letter
Canonical Combining Class	Not Reordered
Bidirectional Class	Left To Right
Decomposition Type	Font
Decomposition Mapping	"u" U+0075 Latin Small Letter U

Encodings

HTML Decimal Encoding	𝕦
HTML Hex Encoding	𝕦
UTF-8 Encoding	0xF0 0x9D 0x95 0xA6
UTF-16 Encoding	0xD835 0xDD66
UTF-32 Encoding	0x0001D566
C/C++/Java Escape	\ud835\udd66

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	"u" U+0075 Latin Small Letter U
NFKC Simple Casefold	"u" U+0075 Latin Small Letter U
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