| oappend | Darcs.UI.Options.Core, Darcs.UI.Options | 
| Object | Darcs.Patch.Prim.V3.ObjectMap, Darcs.Patch.Prim.V3.Core | 
| ObjectMap |  | 
| 1 (Type/Class) | Darcs.Patch.Prim.V3.ObjectMap, Darcs.Patch.Prim.V3.Apply | 
| 2 (Data Constructor) | Darcs.Patch.Prim.V3.ObjectMap, Darcs.Patch.Prim.V3.Apply | 
| obliterate | Darcs.UI.Commands.Unrecord | 
| ocheck | Darcs.UI.Options.Core, Darcs.UI.Options | 
| odesc | Darcs.UI.Options.Core, Darcs.UI.Options | 
| oempty | Darcs.UI.Options.Core, Darcs.UI.Options | 
| oid | Darcs.UI.Options.Core, Darcs.UI.Options | 
| oimap | Darcs.UI.Options.Core, Darcs.UI.Options | 
| Okay | Darcs.Patch.Conflict | 
| okayHash | Darcs.Repository.Cache | 
| OldFormat | Darcs.Patch.Format | 
| oldGlobalCacheDir | Darcs.Repository.Prefs | 
| oldRepoFailMsg | Darcs.Repository.Old | 
| Once |  | 
| 1 (Data Constructor) | Darcs.UI.Options.Flags, Darcs.UI.Flags | 
| 2 (Data Constructor) | Darcs.UI.Options.All | 
| OneHash |  | 
| 1 (Data Constructor) | Darcs.UI.Options.Flags, Darcs.UI.Flags | 
| 2 (Data Constructor) | Darcs.Patch.Match, Darcs.UI.Options.Matching, Darcs.UI.Options.All | 
| OnePatch |  | 
| 1 (Data Constructor) | Darcs.UI.Options.Flags, Darcs.UI.Flags | 
| 2 (Data Constructor) | Darcs.Patch.Match, Darcs.UI.Options.Matching, Darcs.UI.Options.All | 
| OnePattern |  | 
| 1 (Data Constructor) | Darcs.UI.Options.Flags, Darcs.UI.Flags | 
| 2 (Data Constructor) | Darcs.Patch.Match, Darcs.UI.Options.Matching, Darcs.UI.Options.All | 
| OneTag |  | 
| 1 (Data Constructor) | Darcs.UI.Options.Flags, Darcs.UI.Flags | 
| 2 (Data Constructor) | Darcs.Patch.Match, Darcs.UI.Options.Matching, Darcs.UI.Options.All | 
| OnlyChangesToFiles | Darcs.UI.Options.Flags, Darcs.UI.Flags | 
| onlyToFiles | Darcs.UI.Options.All | 
| onormalise | Darcs.UI.Options.Core, Darcs.UI.Options | 
| oparse | Darcs.UI.Options.Core, Darcs.UI.Options | 
| OperationTimeout | Darcs.Util.Download.Request, Darcs.Util.Download | 
| optAbsPathArg | Darcs.UI.Options.Util | 
| optDescr | Darcs.UI.Options | 
| optimize | Darcs.UI.Commands.Optimize | 
| optimizePatchIndex | Darcs.UI.Options.All | 
| option | Darcs.Patch.ReadMonads | 
| optionsMarkdown | Darcs.UI.Options.Markdown, Darcs.UI.Options | 
| OptSpec |  | 
| 1 (Type/Class) | Darcs.UI.Options.Core, Darcs.UI.Options | 
| 2 (Data Constructor) | Darcs.UI.Options.Core, Darcs.UI.Options | 
| optStrArg | Darcs.UI.Options.Util | 
| orClauses | Darcs.Util.English | 
| Origin | Darcs.Patch.Set | 
| OS | Storage.Hashed.Packed | 
| osxCacheDir | Darcs.Util.File | 
| ounparse | Darcs.UI.Options.Core, Darcs.UI.Options | 
| Output |  | 
| 1 (Data Constructor) | Darcs.UI.Options.Flags, Darcs.UI.Flags | 
| 2 (Type/Class) | Darcs.UI.Options.All | 
| 3 (Data Constructor) | Darcs.UI.Options.All | 
| output | Darcs.UI.Options.All | 
| OutputAutoName |  | 
| 1 (Data Constructor) | Darcs.UI.Options.Flags, Darcs.UI.Flags | 
| 2 (Data Constructor) | Darcs.UI.Options.All | 
| overlay | Storage.Hashed.Tree | 
| ownName | Darcs.Util.Path |