Index - O
| odd | Overture |
| on | Overture |
| onException | Overture |
| openBinaryFile | Overture |
| openBinaryTempFile | Overture |
| openBinaryTempFileWithDefaultPermissions | Overture |
| openFile | Overture |
| OpenPunctuation | Overture |
| openTempFile | Overture |
| openTempFileWithDefaultPermissions | Overture |
| optional | Overture |
| or | Overture |
| Ord | Overture |
| ord | Overture |
| Ordering | Overture |
| OtherLetter | Overture |
| OtherNumber | Overture |
| OtherPunctuation | Overture |
| OtherSymbol | Overture |
| otherwise | Overture |
| outputNL | Overture |
| Overflow | Overture |