U+039E "Ξ" Greek Capital Letter Xi Unicode Character
U+039E "Ξ" Greek Capital Letter Xi is the uppercase form of the fourteenth letter in the Greek alphabet, derived from the Phoenician letter samekh. In ancient Greek, it represented the voiceless velar fricative /ks/ sound, a role it retains in modern Greek transcription. Beyond its linguistic function, this symbol is widely used in mathematics and science to denote the xi function in number theory and Riemann zeta function studies, as well as in particle physics for certain baryons. In typography, it appears as a distinctive three horizontal strokes character, often confused with the Cyrillic letter "З" or the lowercase xi "ξ" when capitalisation is overlooked. Its numeric value in the Greek numeral system is 60, and it is encoded in Unicode under the Greek and Coptic block.
General Properties
| Code Point | U+039E |
| Version Added | 1.1 |
| Name | Greek Capital Letter Xi |
| Block | Greek and Coptic |
| General Category | Uppercase Letter |
| Canonical Combining Class | Not Reordered |
| Bidirectional Class | Left To Right |
Encodings
| HTML Decimal Encoding | Ξ |
| HTML Hex Encoding | Ξ |
| UTF-8 Encoding | 0xCE 0x9E |
| UTF-16 Encoding | 0x039E |
| UTF-32 Encoding | 0x0000039E |
| C/C++/Java Escape | \u039e |
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 | "ξ" U+03BE Greek Small Letter Xi |
| Lowercase Code Point | "ξ" U+03BE Greek Small Letter Xi |
| Simple Case Folding | "ξ" U+03BE Greek Small Letter Xi |
| Case Folding | "ξ" U+03BE Greek Small Letter Xi |
| Cased | Yes |
| Changes When Casefolded | Yes |
| Changes When Casemapped | Yes |
| Changes When Lowercased | Yes |
| Changes When NFKC Casefolded | Yes |
| NFKC Casefold | "ξ" U+03BE Greek Small Letter Xi |
| NFKC Simple Casefold | "ξ" U+03BE Greek Small Letter Xi |
| 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 |