U+1D4AA "𝒪" Mathematical Script Capital O Unicode Character

U+1D4AA "𝒪" Mathematical Script Capital O is a typographic letterform used primarily in mathematical and scientific notation to represent a variable, function, or set, often distinct from a standard capital O to avoid confusion with the number zero or other alphanumeric symbols. This character belongs to the Mathematical Alphanumeric Symbols block, which was introduced in Unicode version 3.1 to support the specific formatting needs of mathematical texts, such as those in algebra, calculus, or logic. Its script style mimics a cursive or calligraphic appearance, making it a common choice in academic papers and textbooks for denoting mathematical objects like the set of orthogonal matrices or a Landau symbol in complexity theory.

General Properties

Code Point	U+1D4AA
Version Added	3.1
Name	Mathematical Script Capital O
Block	Mathematical Alphanumeric Symbols
General Category	Uppercase Letter
Canonical Combining Class	Not Reordered
Bidirectional Class	Left To Right
Decomposition Type	Font
Decomposition Mapping	"O" U+004F Latin Capital Letter O

Encodings

HTML Decimal Encoding	𝒪
HTML Hex Encoding	𝒪
UTF-8 Encoding	0xF0 0x9D 0x92 0xAA
UTF-16 Encoding	0xD835 0xDCAA
UTF-32 Encoding	0x0001D4AA
C/C++/Java Escape	\ud835\udcaa

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	"o" U+006F Latin Small Letter O
NFKC Simple Casefold	"o" U+006F Latin Small Letter O
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