Here is a list of all documented struct and union fields with links to the struct/union documentation for each field:

### - u -

- UnfocusFocusedWidget() : Window
- uninit_read : SaveLoadFormat
- uninit_write : SaveLoadFormat
- Uninitialize() : AI
- unique_id : ContentInfo
- unitnumber_digits : BaseVehicleListWindow
- units : LocaleSettings
- units_volume : CargoSpec
- UnreserveSingleTrack() : CYapfReserveTrack< Types >
- Unselect() : ClientNetworkContentSocketHandler
- UnselectAll() : ClientNetworkContentSocketHandler
- UNSELECTED : ContentInfo
- UnselectVehicle() : VehicleGroupWindow
- unshaded_size : Window
- UnshareOrders() : AIOrder
- unwanted : Town
- UpdateDeltaXY() : Aircraft , EffectVehicle , RoadVehicle , Ship , Train , Vehicle , DisasterVehicle
- UpdateListPosition() : NewGRFAddWindow
- UpdateOptionWidgetStatus() : BuildRoadToolbarWindow
- UpdateOrderTimetable() : OrderList
- UpdateOskState() : OskWindow
- UpdatePosition() : ViewportSign , Scrollbar
- UpdateSelectionStates() : TimetableWindow
- UpdateSpeed() : Train
- UpdateStatistics() : BaseGraphWindow
- UpdateViewport() : Vehicle
- UpdateViewportCoordinates() : NWidgetViewport
- UpdateVirtCoord() : BaseStation , Sign , Station , Town , Waypoint
- UpdateWidgetSize() : OrdersWindow , MessageOptionsWindow , BuildRailStationWindow , NewsWindow , NewGRFWindow , NewGRFAddWindow , GameOptionsWindow , NetworkClientListWindow , NetworkClientListPopupWindow , NetworkLobbyWindow , BuildIndustryWindow , NetworkGameWindow , NetworkContentListWindow , NetworkChatWindow , IndustryViewWindow , MusicTrackSelectionWindow , IndustryDirectoryWindow , SelectGameWindow , StationViewWindow , LandInfoWindow , AboutWindow , BuildTreesWindow , ErrmsgWindow , TooltipsWindow , GameDifficultyWindow , QueryStringWindow , QueryWindow , VehicleGroupWindow , PerformanceRatingDetailWindow , CompanyLeagueWindow , SaveLoadWindow , BaseGraphWindow , GameSettingsWindow , CreateScenarioWindow , MusicWindow , EnginePreviewWindow , DepotWindow , SetDateWindow , TownAuthorityWindow , CompanyWindow , StatusBarWindow , SelectCompanyLiveryWindow , CustomCurrencyWindow , CheatWindow , BuildVehicleWindow , BuildBridgeWindow , MessageHistoryWindow , AIDebugWindow , NetworkJoinStatusWindow , AISettingsWindow , RefitWindow , VehicleViewWindow , AIListWindow , NetworkStartServerWindow , AIConfigWindow , VehicleListWindow , ReplaceVehicleWindow , VehicleDetailsWindow , SelectStationWindow< T > , TimetableWindow , PaymentRatesGraphWindow , GenerateProgressWindow , Window , TownDirectoryWindow , BuyCompanyWindow , SelectCompanyManagerFaceWindow , CompanyFinancesWindow , SignListWindow , CompanyStationsWindow , TownViewWindow , ScenarioEditorToolbarWindow , GenerateLandscapeWindow , SubsidyListWindow
- upgrade : ContentInfo
- upper_halftile : ResolverObject
- url : NetworkHTTPContentConnecter , ContentInfo
- use_left_mouse_button : TooltipsWindow
- use_password : NetworkCompanyInfo , NetworkGameInfo
- UseAsRandomAI() : AIInfo
- used : AILog::LogData
- used_set : BaseMedia< Tbase_set >
- UsePaletteAnimation() : Blitter_Null , Blitter_32bppAnim , Blitter_32bppBase , Blitter_8bppBase , Blitter
- user_def_data : RailVehicleInfo