Here is a list of all documented functions, variables, defines, enums, and typedefs with links to the documentation:

### - u -

- UDP_COMMAND : udp.cpp
- UninitFreeType() : fontcache.cpp , fontcache.h
- UnInitWindowSystem() : window.cpp , window_func.h
- UniqueLanguageFile() : strings.cpp
- UnloadFace() : fontcache.cpp
- UnloadWagonOverrides() : newgrf_engine.cpp , newgrf_engine.h
- UNMOVABLE_HQ : unmovable_map.h
- UNMOVABLE_LIGHTHOUSE : unmovable_map.h
- UNMOVABLE_OWNED_LAND : unmovable_map.h
- UNMOVABLE_STATUE : unmovable_map.h
- UNMOVABLE_TRANSMITTER : unmovable_map.h
- UnmovableType : unmovable_map.h
- UnpackOldOrder() : order_sl.cpp , saveload_internal.h
- UnpackVersion4Order() : order_sl.cpp
- UnreserveRailTrack() : pbs.cpp , pbs.h
- UnreserveTrack() : rail_map.h
- UnScaleByZoom() : zoom_func.h
- UnScaleByZoomLower() : zoom_func.h
- UPARROW : widget.cpp
- UpdateAircraftCache() : aircraft.h , aircraft_cmd.cpp
- UpdateAircraftSpeed() : aircraft_cmd.cpp
- UpdateAirplanesOnNewStation() : aircraft.h , aircraft_cmd.cpp
- UpdateAirportsNoise() : station_cmd.cpp , station_func.h
- UpdateAllSignVirtCoords() : signs.cpp , signs_func.h
- UpdateAllStationVirtCoords() : station_cmd.cpp , station_func.h
- UpdateAllTownVirtCoords() : town.h , town_cmd.cpp
- UpdateAllVirtCoords() : afterload.cpp , viewport_func.h
- UpdateCompanyRatingAndValue() : economy.cpp , economy_func.h
- UpdateHousesAndTowns() : saveload_internal.h , town_sl.cpp
- UpdateLevelCrossing() : road_func.h , train_cmd.cpp
- UpdateNearestTownForRoadTiles() : road_cmd.h , road_cmd.cpp
- UpdateNetworkGameWindow() : network_gui.cpp , network_internal.h
- UpdateNewGRFConfigPalette() : gfxinit.cpp , newgrf_config.cpp
- UpdateNumEngineGroup() : group_cmd.cpp
- UpdateOldAircraft() : saveload_internal.h , vehicle_sl.cpp
- UpdateOrderDest() : order_cmd.cpp , order_func.h
- UpdateOSKOriginalText() : osk_gui.cpp , querystring_gui.h
- UpdateSignalsAroundSegment() : signal.cpp
- UpdateSignalsInBuffer() : signal.cpp , signal_func.h
- UpdateSignalsOnSegment() : signal_func.h , signal.cpp
- UpdateStationAcceptance() : station_cmd.cpp , station_func.h
- UpdateTextBufferSize() : textbuf_gui.h , misc_gui.cpp
- UpdateTileSelection() : viewport.cpp , tilehighlight_func.h
- UpdateTownGrowRate() : town_cmd.cpp
- UpdateTrainGroupID() : group.h , group_cmd.cpp
- UpdateTrainPowerProc() : rail_cmd.cpp
- UpdateViewportPosition() : viewport.cpp , viewport_func.h
- UpdateWaypointOrder() : station_sl.cpp , waypoint_sl.cpp
- UpdateWindows() : window.cpp , gfx_func.h
- usererror() : openttd.cpp
- UsesWagonOverride() : newgrf_engine.cpp , newgrf_engine.h
- Utf8CharLen() : string_func.h
- Utf8EncodedCharLen() : string_func.h
- Utf8PrevChar() : string_func.h
- Utf8TrimString() : string.cpp , string_func.h