U+00CF "Ï" Latin Capital Letter I with Diaeresis Unicode Character
Unicode Version 17.0
Ï
U+00CF "Ï" Latin Capital Letter I with Diaeresis is a composed letter used in several languages, including French, Dutch, and English, to indicate that the letter I is pronounced separately from a preceding vowel, as in the French word "naïf" or the English name "Zoë," thereby preventing it from forming a digraph or diphthong. This character is formed by placing two dots, known as a diaeresis or umlaut, above the capital letter I, and it differs from a simple I in both visual appearance and phonetic function. In computing, it is distinct from the standalone letter I and the combining diaeresis mark (U+0308), allowing for precise text rendering and linguistic accuracy in digital environments.
General Properties
| Code Point | U+00CF |
| Version Added | 1.1 |
| Name | Latin Capital Letter I with Diaeresis |
| Unicode 1.0 Name | Latin Capital Letter I Diaeresis |
| Block | Latin-1 Supplement |
| General Category | Uppercase Letter |
| Canonical Combining Class | Not Reordered |
| Bidirectional Class | Left To Right |
| Decomposition Type | Canonical |
| Decomposition Mapping | "I" U+0049 Latin Capital Letter I "̈" U+0308 Combining Diaeresis |
Encodings
| HTML Decimal Encoding | Ï |
| HTML Hex Encoding | Ï |
| UTF-8 Encoding | 0xC3 0x8F |
| UTF-16 Encoding | 0x00CF |
| UTF-32 Encoding | 0x000000CF |
| C/C++/Java Escape | \u00cf |
Unicode Properties
| NFC Quick Check | Yes |
| NFKC Quick Check | Yes |
| Numeric Type | None |
| Numeric Value | NaN |
| Line Break | Alphabetic |
| Uppercase | Yes |
| Simple Lowercase Code Point | "ï" U+00EF Latin Small Letter I with Diaeresis |
| Lowercase Code Point | "ï" U+00EF Latin Small Letter I with Diaeresis |
| Simple Case Folding | "ï" U+00EF Latin Small Letter I with Diaeresis |
| Case Folding | "ï" U+00EF Latin Small Letter I with Diaeresis |
| Cased | Yes |
| Changes When Casefolded | Yes |
| Changes When Casemapped | Yes |
| Changes When Lowercased | Yes |
| Changes When NFKC Casefolded | Yes |
| NFKC Casefold | "ï" U+00EF Latin Small Letter I with Diaeresis |
| NFKC Simple Casefold | "ï" U+00EF Latin Small Letter I with Diaeresis |
| Script | Latin |
| Script Extensions | Latin |
| 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 |