Global AircraftController (Aircraft *v)

De-mystify the cur_speed values for helicopter rotors.

Global CmdBuildRoadDepot (DoCommandFlag flags, TileIndex tile, RoadType rt, DiagDirection dir)

When checking for the tile slope, distinguish between "Flat land required" and "land sloped in wrong direction"

Global CmdBuildSingleSignal (DoCommandFlag flags, TileIndex tile, Track track, SignalType sigtype, SignalVariant sigvar, bool convert_signal, bool skip_existing_signals, bool ctrl_pressed, SignalType cycle_start, SignalType cycle_stop, uint8_t num_dir_cycle, uint8_t signals_copy)

p2 should be replaced by two bits for "along" and "against" the track.

Global CmdBuildTrainDepot (DoCommandFlag flags, TileIndex tile, RailType railtype, DiagDirection dir)

When checking for the tile slope, distinguish between "Flat land required" and "land sloped in wrong direction"

Global CmdBuyCompany (DoCommandFlag flags, CompanyID target_company, bool hostile_takeover)

currently this only works for AI companies

Global CommonRaiseLowerBigLand (TileIndex tile, bool mode)

: Incorporate into game itself to allow for ingame raising/lowering of larger chunks at the same time OR remove altogether, as we have 'level land' ?

Global CYapfCostRailT< Types >::max_cost

fix maximum cost failing with caching (e.g. FS#2900)

Class NWidgetViewport

Class derives from NWidgetCore, but does not use colour, widget_data, or tool_tip.

Global PropertyID

Currently the list only contains properties which are used more than once in the code. I.e. they are available for callback 0x36.

File sprites.h

Split the "Sprites" enum into smaller chunks and document them

File tunnelbridge_cmd.cpp

separate this file into two