### - u -

- underlined : Font
- unknown : AudioCDBurner , AudioChannelSet , Block , RelativeCoordinate::StandardStrings
- UnknownFormat : Image
- UnknownHost : PluginHostType
- UnknownOS : SystemStats
- unspecified : PushNotifications::Notification
- up : ControlButton , DrumPadGridProgram
- upDownButtonArrowColourId : MidiKeyboardComponent
- upDownButtonBackgroundColourId : MidiKeyboardComponent
- UpDownLeftRightResizeCursor : MouseCursor
- UpDownResizeCursor : MouseCursor
- upright : Desktop
- upsideDown : Desktop
- urlKeyboard : TextInputTarget
- useDefaultValue : GridItem
- useHiddenFile : TemporaryFile
- userApplicationDataDirectory : File
- userCancelledSave : FileBasedDocument
- userDesktopDirectory : File
- userDocumentsDirectory : File
- userHomeDirectory : File
- userMoviesDirectory : File
- userMusicDirectory : File
- userPicturesDirectory : File
- useTreeView : FileBrowserComponent