### - o -

- obj_len : SaveLoadParams
- occupied : RoadStop::Entry
- offs_base : SaveLoadParams
- offset : Blitter_8bppOptimized::SpriteData , OldChunks , BmpInfo , CompanyManagerFaceBitsInfo , LoggedChange
- offsets : LanguagePackHeader
- oil_refinery : ExtraPaletteValues
- oil_refinery_limit : GameCreationSettings
- ok_btn : OskWindow
- okay : PBSTileInfo
- old : Vehicle
- old_max_loan_unround : Economy
- old_max_loan_unround_fract : Economy
- old_refittable : ShipVehicleInfo
- old_tile : GetNewVehiclePosResult
- oldval : LoggedChange
- online : NetworkGameList
- opf : PathfinderSettings
- order : GameSettings , Listing , RefitWindow
- order_review_system : GUISettings
- ordinal_width : CompanyLeagueWindow
- orientation : RailStationGUISettings
- orig_list : NewGRFWindow
- orig_str_buf : OskWindow
- original_image_index : Engine
- os2_bmp : BmpInfo
- other_company_name : CompanyNewsInformation
- override : GRFFileProps , HouseSpec
- own_name : LanguagePackHeader
- owner : BaseStation , Group , CargoPayment , Industry , Window , TileDesc
- owner_type : TileDesc