U+039F "Ο" Greek Capital Letter Omicron Unicode Character

U+039F "Ο" Greek Capital Letter Omicron is the uppercase form of the fifteenth letter in the Greek alphabet, which holds a long and important history as the ancestor of the Latin letter "O" and is commonly used in modern Greek writing for the sound /o/. In mathematics and science, it often symbolizes the omicron function or concepts like the big O notation for asymptotic growth, though it can be easily confused with the visually identical Latin capital "O" in digital text. This character also gained public attention during the COVID-19 pandemic when the World Health Organization designated it as the name for the highly transmissible Omicron variant.

General Properties

Code Point	U+039F
Version Added	1.1
Name	Greek Capital Letter Omicron
Block	Greek and Coptic
General Category	Uppercase Letter
Canonical Combining Class	Not Reordered
Bidirectional Class	Left To Right

Encodings

HTML Decimal Encoding	Ο
HTML Hex Encoding	Ο
UTF-8 Encoding	0xCE 0x9F
UTF-16 Encoding	0x039F
UTF-32 Encoding	0x0000039F
C/C++/Java Escape	\u039f

Unicode Properties

NFC Quick Check	Yes
NFD Quick Check	Yes
NFKC Quick Check	Yes
NFKD Quick Check	Yes
Numeric Type	None
Numeric Value	NaN
Line Break	Alphabetic
East Asian Width	Ambiguous
Uppercase	Yes
Simple Lowercase Code Point	"ο" U+03BF Greek Small Letter Omicron
Lowercase Code Point	"ο" U+03BF Greek Small Letter Omicron
Simple Case Folding	"ο" U+03BF Greek Small Letter Omicron
Case Folding	"ο" U+03BF Greek Small Letter Omicron
Cased	Yes
Changes When Casefolded	Yes
Changes When Casemapped	Yes
Changes When Lowercased	Yes
Changes When NFKC Casefolded	Yes
NFKC Casefold	"ο" U+03BF Greek Small Letter Omicron
NFKC Simple Casefold	"ο" U+03BF Greek Small Letter Omicron
Script	Greek
Script Extensions	Greek
Indic Syllabic Category	Other
ID Start	Yes
XID Start	Yes
ID Continue	Yes
XID Continue	Yes
Alphabetic	Yes
Vertical Orientation	Rotated
Grapheme Base	Yes
Grapheme Cluster Break	Other
Word Break	Alphabetic letter
Sentence Break	Upper