| U+ | art-254 |
| 00D6 | |
| Unicode Character Names | art-315 | LATIN CAPITAL LETTER O DIAERESIS |
| Unicode Character Names | art-315 | LATIN CAPITAL LETTER O WITH DIAERESIS |
| American English | eng-004 | LATIN CAPITAL LETTER O WITH DIAERESIS |
| français | fra-000 | LETTRE MAJUSCULE LATINE O TRÉMA |