| FAEX | A.E. Fagan | added 4/54; 10/57 |
| FAIX | FAIX Leasing, Inc. | Jul-00 |
| FALX | Falk Corp. | 1/80-7/2000 |
| FAPR | Floydada and Plainview R.R. Co. | added 7/90; 1/94; eliminated 1/95; 7/2000 |
| FARX | Farmers Cooperative Co. of Cleghorn, Ia | added 7/80; eliminated 1/90 |
| FBCX | Foley Butane Co., Inc. | 1/52-10/57 |
| FBDC | Ford County Historical R.R. Preservation Foundation | 1/94-7/2000 |
| FBL | Federal Barge Lines, Inc. | 10/57-10/66 & 1/75 |
| FBMX | Fayblock Materials | added 10/96; eliminated 4/97; 7/2000 |
| FBRX | Fiske Brothers Refining Co. | 4/38-10/66; eliminated 1/70 |
| FC | Fulton County R.R., Inc. | Jul-00 |
| FCCM | Compania de Ferrocarriles Chiapas Mayab S.A. de C.V. | Jul-00 |
| FCCX | Farmers Cooperative Co. | added 4/80; eliminated 10/89 |
| Foxley Cattle Co. | 1/94-7/2000 | |
| FCDN | Ferrocarril de Nacozari, Sct. | 1/75-1/80 |
| FCEN | Florida Central R.R. Co., Inc. | added 4/87; 1/94 |
| Pinsly R.R. Co. | eliminated 4/97 | |
| Florida Central R.R. Co., Inc. | added 4/97; 7/2000 | |
| FCEX | Fruit Growers Express Co. | 1/52; eliminated 10/53 |
| FCEX | Farmers Union Central Exchange, Inc. | added 10/74; 1/75-1/94; eliminated 7/94 |
| CENEX, Inc. | added 7/94; eliminated 4/99 | |
| Cenex Harvest States Cooperative | added 4/99; 7/2000 | |
| FCIN | Frankfort & Cincinnati R.R. Co. | 1/75-1/80; eliminated 4/86 |
| FCM | Compania del Ferrocarril Mexicano | 1/52-10/57 |
| Ferrocarril Mexicano | 4/61-7/65 | |
| Ferrocarriles Nacionales de Mexico | 10/66-4/70 | |
| Ferrocarriles Mexicano (Mexican) | 1/75-1/80 | |
| Ferrocarriles Nacionales de Mexico | 1/94-7/2000 | |
| FCOX | FLO CO (superscript: 2) Inc. | Jul-00 |
| FCP | Ferrocarril del Pacifico, S.A. de C.V. | 10/57-10/66 & 1/75-1/80; eliminated 4/88 |
| Ferrocarriles Nacionales de Mexico-Region Pacifico | added 4/88; eliminated 10/88 | |
| Ferrocarriles Nacionales de Mexico-Region Pacifico (transferred to Ferrocarriles Nacionales de Mexico) | added 10/88 | |
| Ferrocarriles Nacionales de Mexico | 1/94-7/2000 | |
| FCRK | Falls Creek R.R. Co. | eliminated 4/89 |
| FCRX | Franklin Creek Refining Corp. | Apr-38 |
| FCSX | Florida Crushed Stone Co. | added 7/84; 1/94-7/2000 |
| FCTX | Famers Commodities Transportation Co. | added 1/97; 7/2000 |
| FCWX | Southwide, Inc. | added 1/74; 1/75; eliminated 4/78 |
| FCX | Fuelane Corp. | 1/52-10/57; eliminated 7/59 |
| FCYR | Franklin County R.R. Corp. | added 4/86; eliminated 4/88 |
| FDDM | Chicago and North Western Transportation Co. (Fort Dodge, Des Moines & Southern Ry. Co.)) | Jan-75 |
| Chicago and North Western Transportation Co. | 1/80-1/94; eliminated 1/95 | |
| Chicago and North Western Ry. Co. | added 1/95; eliminated 10/95 | |
| Union Pacific R.R. Co. | added 10/95; 7/2000 | |
| FDEX | Fruit Growers Express Co. | 4/38-4/70; eliminated 10/74; 1/75 |
| FDMA | Ferrocarril de Minatitlan al Carmen | 1/75-1/80 |
| FEC | Florida East Coast Ry. Co. | 1/75-7/2000 |
| FEIX | Farmers Elevator, Inc. of Grace City | 1/80-7/2000 |
| FELX | Fels & Co. | 4/38-4/61; eliminated 7/64 |
| Purex Corp., Ltd. | added 7/64; 7/65 | |
| Fels & Co. (Purez Corp., Ltd.) | Oct-66 | |
| Purex Corp., Ltd. | 4/70; eliminated 10/70 | |
| Farmers Elevator Co. of Westhope, N.D. | added 1/81; eliminated 10/83 | |
| FEMX | Freight Equipment Management Co. | added 7/78; 1/80; eliminated 4/89 |
| FERR | Feliciana Eastern R.R. Co. | 1/75-1/80 |
| FFCX | The Farmers Fertilizer Co. | Apr-38 |
| FFCX | Foremost International, S.A. | added 4/68; 4/70; eliminated 10/70 |
| FFIX | Union Tank Car Co. | added 7/73; eliminated 1/74 |
| FFIX | Procor Ltd. | added 1/74; 1/75-7/2000 |
| FFTX | Fun Trains, Inc. | Jul-00 |
| FGCX | Fruit Growers Express Co. | 4/61-1/80; eliminated 10/81; eliminated 1/82 |
| Florida Gulf Coast R.R. Museum, Inc. (passenger cars) | 1/94-7/2000 | |
| FGER | Fruit Growers Express Co. | added 1/80; 1/80-7/2000 |
| FGEX | Fruit Growers Express Co. | 4/38-10/66 & 1/75-1/80; eliminated 10/80 |
| Fremont Grain Co. | added 1/88 | |
| FGFX | Fremont Grain Co. | eliminated 7/89 |
| FGGX | Farmers Grain Cooperative | added 10/90; 1/94-7/2000 |
| FGIX | Farmer's Grain and Feed Co., Inc. | 1/75-1/80 |
| FGLK | Finger Lakes Ry. Corp. | added 10/95; 7/2000 |
| Factor Gas Liquids Inc. | added 1/96; 7/2000 | |
| FGMR | Fruit Growers Express Co. | added 10/80; 1/94-7/2000 |
| FG&S | Farmers' Grain & Shipping Co. | Apr-38 |
| FGTX | Florida Gas Terminals, Inc. | eliminated 10/91 |
| FGWX | Federal Grain Inspection Service (test scale cars) | Jan-94 |
| Federal Grain Inspection Service (USDA) (test scale cars) | Jul-00 | |
| FHIX | Fruit Growers Express Co. | 1/52-1/75; eliminated 7/78 |
| FHRR | Ferdinand & Huntingburg R.R. Co. | added 4/88; eliminated 10/91; 1/94 |
| FILX | Fiber Industries, Inc. | added 10/88; eliminated 10/92 |
| FILX | Wellman, Inc. | added 10/92; 1/94-7/2000; eliminated 4/2001 |
| Finley Co. Inc. | 10/57-10/66; eliminated 10/67 | |
| Trinity Rail Management, Inc. | added 4/98; 7/2000 | |
| FIR | Flats Industrial R.R. Co. | Jul-00 |
| FJG | Fonda, Johnstown & Gloversville R.R. Co. | 1/75; added 4/75; 1/80; eliminated 10/88 |
| Fonda, Johnstown & Gloversville R.R. Co. (transferred to New York, Susquehanna and Western Ry. Corp.) | added 10/88 | |
| The New York, Susquehanna and Western Ry. Corp. | eliminated 4/91 | |
| FLGX | Flamegas Leasing Corp. | added 1/74 |
| FJLX | Big West Oil Co. | 1/94-7/2000 |
| FKRX | Flintkote Roads, Ltd. (Colas Roads, Ltd.) | Apr-38 |
| Flintkote Co. of Canada Ltd. | 1/52-7/65 | |
| Colas Roads, Ltd. (Flintkote Co. of Canada Ltd.) | Oct-66 | |
| The Flintkote Co. of Canada Ltd. | 4/70; eliminated 10/71 | |
| FLAX | Flexsys America L.P. | Jul-00 |
| FLCX | Flex Leasing Corp. | added 7/97; 7/2000 |
| FLDX | DTE Transportation Services, Inc. | Jul-00 |
| FLEX | RailLease Inc. | 1/94-7/2000 |
| FLGX | Flamegas Transportation Systems, Inc. | Jan-75 |
| FLIX | Farmland Industries, Inc. | added 1/74; 1/75-7/2000 |
| FLJX | Big West Oil Co. | added 10/93; 1/94-7/2000 |
| FLNX | R.P. Flynn, Inc., d/b/a Ohio Railway Supply | Jul-00 |
| FLOX | Float-Away Door Co. | Apr-70 |
| Flex Leasing Corp. | added 7/97; 7/2000 | |
| FLRX | Fabrica de Jabon "La Rainera", S.A. | 1/52-10/57; eliminated 1/59 |
| ADM Milling Co. | added 1/94-7/2000 | |
| FLSX | Great Miami, Inc. | 1/94; added 1/97; eliminated 4/2000; 7/2000 |
| FLT | Foss Launch & Tug | 1/75-7/2000 |
| FMCX | First Mississippi Corp. | added 10/58; 4/61-10/66; eliminated 1/70 |
| Transerv Systems, Inc. | added 1/70; 4/70; eliminated 1/72 | |
| First Mississippi Corp. | added 1/72; 1/75 | |
| FMID | Florida Midland R.R. Co., Inc. | added 1/88; 1/94-7/2000 |
| FMIX | Fairbanks Morse, Inc. | Apr-70 |
| Fabricated Metals, Inc. | added 1/86; eliminated 7/86 | |
| CCKX, Inc. | 1/94; eliminated 7/99; 7/2000 | |
| FMLX | FMC Corp. | 7/65-10/66 |
| FMC Corp., Inorganic Chemicals Division | 4/70-1/80 | |
| FMC Corp. | 1/94-7/2000 | |
| FMOX | FMC Corp. | added 10/65; 10/66 |
| FMC Corp., Inorganic Chemicals Division | 4/70-1/80 | |
| FMC Corp. | eliminated 7/93; 1/94; eliminated 10/97; 7/2000 | |
| FMRC | Farmrail Corp. | added 4/82; 1/94; eliminated 7/94; eliminated 10/95; 7/2000 |
| FMS | Fort Myers Southern R.R. Co. | 1/75-1/80 |
| FMTX | Freeport Mexican Fuel Oil Corp. (Sinclair Refining Co.) | Apr-38 |
| Sinclair Refining Co. | 1/52-10/57; eliminated 1/58 | |
| Sinclair Cuba Oil Co., S.A. | added 1/58 | |
| FMYX | F.M. Yorke & Son, Ltd. | 1/52-1/75 |
| FNAX | Ferrellgas, L.P. | Jul-00 |
| FNE | Ferrocarriles Nacionales de Mexico | added 4/96; eliminated 10/97 |
| TFM, S.A. de C.V. | added 10/97; eliminated 4/99; 7/2000 | |
| FNOR | Florida Northern R.R. Co. Inc. | 1/94-7/2000 |
| FOBX | Fruit Growers Express Co. | 1/52-1/75; eliminated 4/75 |
| FOKX | Fidelity Oil Co. (The British American Oil Co., Ltd.) | Apr-38 |
| British American Oil Co., Ltd. | 1/52-10/57 | |
| Canadian General Transit Co., Ltd. | 4/61; eliminated 4/61 | |
| FOR | Fore River R.R. Corp. | 1/75-1/80 |
| FOWX | The Freedom Oil Works Co. | Apr-38 |
| FOX | J.M. Fox | 10/57; eliminated 1/59 |
| FP | Fordyce & Princeton R.R. Co. | 1/75-1/80; added 4/81; 1/94-7/2000 |
| FPAX | Formosa Plastics Corp. U.S.A. | added 4/81; 1/94; eliminated 1/98 |
| Formosa Transrail Corp. | added 1/98; 7/2000 | |
| FPBX | Federal Paper Board Co., Inc. | added 4/75; 1/80-1/94; eliminated 10/95 |
| FPB Leasing Corp. | added 10/95 | |
| International Paper Co. | added 4/99; 7/2000 | |
| FPCX | Feldman Petroleum Co. | Apr-38 |
| Firestone Plastics Co. | added 7/79; 1/80; eliminated 10/81 | |
| Hooker Chemicals and Plastics Corp. | added 10/81; eliminated 10/82 | |
| Occidental Chemical Corp., PVC Resins | added 10/82; eliminated 1/92 | |
| Occidental Chemical Corp. | added 1/92; 1/94; eliminated 7/99 | |
| Oxy Vinyls L.P. | added 7/99; 7/2000 | |
| FPDX | Forest Products Chemical Co. | 4/38-7/65; eliminated 10/66 |
| FPE | Fairport, Painesville & Eastern R.R. Co. | 4/38-10/66 & 1/75-1/80; eliminated 10/84 |
| FPFX | Foster Poultry Farms, Inc. | added 4/80; 1/94; eliminated 4/97 |
| NorRail, Inc. | added 4/97; eliminated 10/99 | |
| FPN | Ferrocarriles Nacionales de Mexico | added 4/96; 7/2000 |
| FPPX | Fayette Power Project | added 10/78; 1/80-7/2000 |
| FPX | Fleishman's Pickles, Inc. | Apr-38 |
| FRCX | Falling Rock Cannel Coal Co. | Apr-38 |
| Federal Rail Car Corp. | 1/80; eliminated 7/81 | |
| Continental Tank Car Corp. | added 7/81; eliminated 4/87; 1/94 | |
| FRDN | Ferdinand R.R. | 1/75-1/80; added 7/80; eliminated 10/80 |
| Ferdinand R.R. Co. | added 10/80; eliminated 4/88 | |
| Ferdinand & Huntington R.R. | eliminated 4/88 | |
| H&S R.R. Co. | 1/94-7/2000 | |
| FRDX | Ford Motor Co. | 4/38-4/61 |
| FREX | Fremont Elevator Co. | added 7/70; eliminated 10/74 |
| FRMR | Fruit Growers Express Co. | eliminated 1/95 |
| FR&N | Flint River & Northeastern R.R. | 4/38-1/52 |
| FRPX | Filtered Rosin Products Co. | added 10/69; 4/70; eliminated 4/71 |
| FRP Co. | added 4/71; 1/75; eliminated 4/76 | |
| FRR | Falls Road R.R. Co., Inc. | Jul-00 |
| FRTX | Fred Rives Transportation Co., Fred Rives Sr., owner | 1/52-4/61 |
| Fred Rives Transportation Co. | 7/65-10/66 | |
| Fred Rives Transportation Co., Fred Rives Sr., owner | Apr-70 | |
| Frit Industries | added 7/78 | |
| Frit Industries, Inc. | eliminated 1/79 | |
| Frit Transportation, Inc. | added 1/79; 1/80; eliminated 4/91 | |
| Farm-City Transport, Inc. | Jul-00 | |
| FRVR | Fox River Valley R.R. Corp. | added 4/89; eliminated 1/94 |
| Fox Valley & Western, Ltd. | added 1/94; 7/2000 | |
| FRY | Fore River Ry. Co., Inc. | eliminated 10/92; 1/94 |
| FRYX | Frye & Co. | 4/38-4/61 |
| FSCX | Freeport Sulphur Co. | 4/38; added 7/58; eliminated 10/58 |
| Ferro Standard Corp. | added 10/66; 10/66; eliminated 10/68 | |
| Frank Mitacek Railway Service | added 1/83; eliminated 1/89 | |
| FSFL | Burlington Northern Santa Fe Ry. Co. | added 4/2001 |
| FSHX | North American Car Corp. | added 10/74; 1/75-1/80 |
| General Electric Railcar Services Corp. | 1/94; eliminated 1/2000 | |
| General Electric Rail Services Corp. | added 1/2000; 7/2000 | |
| FSIX | Freight Services, Inc. | 1/94; added 10/94; eliminated 10/96 |
| FSIX Inc. | Jul-00 | |
| FSR | Fort Smith R.R. Co. | added 1/92; 1/94-7/2000 |
| FSRR | Ferrocarril del Sureste, S.A. de C.V. | Jul-00 |
| FSRX | Funding Systems Railcars Leasing, Inc. | added 4/81; eliminated 7/82 |
| FST | Ferrocarriles Nacionales de Mexico | added 4/96; 7/2000 |
| FSTX | Fuel Supply Trust | added 1/97; 7/2000 |
| FSUD | Fort Street Union Depot Co. | 1/75-7/2000 |
| FSVB | Fort Smith & Van Buren Ry. Co. | 1/75-7/2000 |
| FSW | Fort Smith & Western R.R. | 4/38-1/52 |
| FSWX | Flamingo Spring Water Co. | Apr-38 |
| Flamingo Water Co. | 1/52; eliminated 1/53 | |
| FSX | National Car Co. | Jan-52 |
| FTCX | The Fleischmann Transportation Co. | Apr-38 |
| Frazier Brokerage Co. | 1/52; eliminated 4/54 | |
| Far Port Cooperative, Inc. | added 1/81; eliminated 1/89 | |
| Chrysler Rail Transportation Corp. | 1/94; eliminated 1/97 | |
| FTIX | Fore Terminal, Inc. | added 7/66; 10/66 & 1/75 |
| FTIX Associates | Jan-80 | |
| FTLX | Fagan Tank Line | 1/52; eliminated 4/54 |
| R.J. Roesing and Co. | added 4/54 | |
| FTSX | Fairmont Tamper | added 1/97; eliminated 7/99; 7/2000 |
| FTTX | Trailer Train Co. | Jul-65 |
| Trailer Train Co. (FMS flat cars specially equipped to provide for loading of automobile frames) | 10/66-10/68 | |
| Trailer Train Co. | Apr-70 | |
| Trailer Train Co. (flat cars equipped with tie-down devices for loading automobile or truck frames) | 1/75-1/80; eliminated 1/92 | |
| TTX Co. (flat cars equipped with tie-down devices for loading automobile or truck frames) | added 1/92; 1/94 | |
| TTX Co. (flat cars equipped with tie-down devices for loading automobile or truck frames, equipped with end of car cush.) | Jul-00 | |
| FTX | Frontier Tank Car Co. | 1/52; eliminated 4/55 |
| General American Transportation Corp. | added 4/55; eliminated 7/55 | |
| FURX | First Union Rail | added 7/95; 7/2000 |
| FUS | Ferrocarriles Unidos del Sureste, S.A. de C.V. | 1/75-1/80 |
| Ferrocarriles Unidos del Sureste, S.A. de C.V. (transferred to Ferrocarriles Nacionales de Mexico) | eliminated 10/88 | |
| Ferrocarriles Nacionales de Mexico | added 10/88; 1/94-7/2000 | |
| FVRR | Fredonia Valley R.R. Inc. | Jul-00 |
| FVW | Fox Valley & Western, Ltd. | added 1/94; 7/2000 |
| FWB | Fort Worth Belt Ry. Co. | Jan-75 |
| FWCR | Florida West Coast R.R., Inc. | added 4/88; 1/94; eliminated 1/98; 7/2000 |
| FW&D | Fort Worth & Denver City Ry. | 4/38-10/57 |
| Fort Worth & Denver Ry. | Apr-61 | |
| FWD | (FW&D) Fort Worth and Denver Ry. Co. | 7/65-10/66 |
| Fort Worth and Denver Ry. Co. | 1/75-1/80; eliminated 1/83 | |
| Burlington Northern R.R. Co. | added 1/83; 1/94 | |
| Burlington Northern Santa Fe Ry. Co. | Jul-00 | |
| FWDB | Fort Worth & Dallas Belt R.R. | Jul-00 |
| FWDR | Fort Worth & Dallas R.R. Co. | 1/94-7/2000 |
| FWDX | Fort Worth-Denver (Burlington Refrigerator Express Co.) | Apr-38 |
| Burlington Refrigerator Express Co. | 1/52-10/57; eliminated 1/59 | |
| FWLX | Foster Wheeler Ltd. | added 4/92; 1/94-7/2000 |
| FWPP | Fremont, West Point & Pacific Ry., Inc. | added 4/88; eliminated 1/91 |
| FWRD | Fairmont and Western R.R. Co. | added 1/85; eliminated 10/88 |
| FWRY | Filmore Western Ry. Co. | Jul-00 |
| FWU | Fort Wayne Union | 1/75-1/80 |
| FWWR | Fort Worth & Western R.R. Co. | added 10/90; 1/94-7/2000 |
| FXE | Ferrocarril Mexicano, S.D. de C.V. | added 4/98; 7/2000 |