Acronyms, Abbreviations & Terms Used in OGR Forums

List of Acronyms, Abbreviations & Terms Frequently used on OGR Forums

To anyone using acronyms on the ORG Forums, a suggestion to help us all:

Before using an acronym don't always assume acronyms you use are well known to all.
Worst of all, many train acronyms are not easy to look up. (eg: the first match for TMCC
on Google is for Truckee Meadows Community College). Please spell out abbreviations for
the first use and resort to an acronym thereafter.

Thanks! - (Borrowed from a post by overlandflyer, edited slightly)

• 2RS - 2-Rail Scale - O Scale on 2 Rails (See OGR 2-Rail Scale Forum)
• 3rd Rail - Manufacturer Of Model Trains and Accessories
• 3RO - 3 Rail O gauge
• 3RS - 3-Rail Scale (See OGR 3-Rail Scale Forum)
• 48 - 4' x 8' (As Used in 48 Club)
• A - Old Generation Transformer Terminal Designation (Often Referring to Voltage Across Two Terminals as in AU, BU, CU etc.)
• AAMOF - As A Matter Of Fact
• ABRM - Automatic Bumper Reverse Mechanism (Term used by MTH)
• ABS - Automatic Block System
• AC - Alternating Current
• ACC - Alpha Cyanoacrylate (aka CA or "Crazy Glue") Also Accessory (or Power for Accessories)
• ACDR - Alternating Current Motor Driver used in TMCC engines
• ACF - America Car And Foundry (Rail Car Manufacturer)
• AF - American Flyer - Manufacturer of Trains And Accessories (Started by A.C. Gilbert - Now Owned by Lionel)
• AFAIAC - As Far As I Am Concerned
• AFAICT - As Far As I Can Tell
• AFAIK - As Far As I Know
• AFU - All Fouled Up
• AIU - Accessory Interface Unit - Add on To MTH's DCS System for Controlling Accessories
• AKA - Also Known As (aka - also used in lower case)
• ALCO - American Locomotive Company
• AMC - Accessory Motor Controller - Controls Motorized Accessories with Lionel TMCC/Legacy System
• ARC - Action Recorder Controller
  For Record/Playback of Layout Train & Accessory Scenarios with Lionel TMCC/Legacy System
• ASC - Accessory Switch Controller
  Controls Accessories & Turnouts with Lionel TMCC/Legacy System
• Atlas-O - Manufacturer Of Model Trains and Accessories
• AVC - Accessory Voltage Controller - For controlling Accessory Voltage with Lionel TMCC/Legacy)
• AWG - American Wire Gauge (Wire Sizes - Smaller Number = Larger Wire)
• B - Old Generation Transformer Terminal Designation
  (Often Referring to Voltage Across Two Terminals as in AU, BU, CU etc.)
• Base-1L - Base Unit for Cab-1L - Required to Communicate with Locomotives and Other Equipment
• BAU - Business As Usual
• BCR - Battery Component Replacement, permanently replaces 9 volt battery in model trains
• BFF - Berwick Forge & Fabricating (Rail Car Manufacturer in Berwick, PA)
• BLE - Bluetooth Low Energy
• BNIB - Brand New In Box (Also see NIB)
• BN - Burlington Northern Rail Road
• BNSF - Burlington Northern Santa Fe Rail Road
• BPC - Block Power Controller - For Controlling Block Power with Lionel TMCC/Legacy System
• BPRC - Battery Power, Remote Control
• BRB - Be Right Back
• Brick - Transformer With Fixed Voltage Output - Usually 18VAC
  (Lionel PowerHouse PH-135, PH-180, MTH Z-500, Z-750, Z-1000 Bricks Only)
• BTDT - Been There, Done That
• BTO - Built To Order also Bachman Turner Overdrive ('70s rock band)
• BTW - By The Way
• BUDD - A Railroad Car Manufacturer
• C - Common Contact Terminal on a Relay (Common to both NO & NC Contacts - See NO & NC)
  Also - Old Transformer Terminal Designation (Often Referring to Voltage Across Two Terminals as in AU, BU, CU etc.)
• CA - Alpha Cyanoacrylate (aka ACC or "Crazy Glue")
• Cab-1 - Remote Unit for Lionel TMCC System
• Cab-1L - Remote Unit for Lionel TMCC & Legacy System - Legacy Lite - Does not Control all Legacy Features
• Cab-2 - Remote for Lionel Legacy System
• C&S - Colorado & Southern Rail Road (Subsidiary of CB&Q)
• CB&Q - Chicago Burlington & Quincy Rail Road (Now BNSF)
• CBL - Crappy Basement Layout
• CC - Command Control (Also Conventional Classics - Lionel Reproduction Sets)
• CC - Cruise Commander (total electronic replacement to add TMCC control capability and cruise control
  (Electric Rail Road Co - See ERR)
• CCA - Copper Coated Aluminum (as in layout wiring - OFC is much preferred for your layout - see OFC below))
• CCM - Cruise Commander M - DCDR replacement to add cruise control
  (Electric Rail Road Co - See ERR)
• CDU - Capacitor Discharge Unit
• Choke - Inductor for Blocking Higher Frequency AC in Electrical Circuits
  Could be needed for DCS Signal Improvement. (22uh for Our Use)
• Clockwork - Mechanical or Wind-Up Train
• COFC - Container On Flat Car
• Command Control - Remote Control Of Trains, Turnouts and Accessories
• CONUS - Contiguous United States (Lower 48 States)
• Conventional - Method of Model Train Control using Transformer Handles as Throttles to Vary Track Voltage (can also be accomplished with DCS/TMCC/Legacy systems)
• CP - Canadian Pacific Rail Road
• CSX - CSX Rail Road
• CTC - Centralized Train Control - Real controls for operation of 1:1 trains (Real Trains)
• CTT - Classic Toy Trains Magazine
• CWR - Continuous Welded Rail
• CZ - California Zephyr
• D - Old Generation Transformer Terminal Designation (Often Referring to Voltage Across Two Terminals as in AU, BU, CU etc.)
• DAP - Dealer Appreciation Program (MTH has one)
• DBA - Doing Business As
• DC - Direct Current
• DCC - Digital Command Control - NMRA Standard Command Control System
  Open Source DC Control - Mostly for HO, N, G & 2 Rail O
• DCC - DC Commander is used in conventional engines with DC motors to upgrade to TMCC without Cruise
  (Electric Rail Road Co - See ERR)
• DCS - Digital Command System by MTH (#50-1001 Includes DCS Remote #50-1002 & TIU #50-1003)
  Can Control TMCC with Lionel Powermaster Bridge & Cable (Also - Delivers Control Satisfaction)
• DCDR - Direct Current Motor Driver used in TMCC engines
• DOA - Dead On Arrival (Sometimes used to describe a new Locomotive Purchase)
• DPP - Double Pulling Power - Term used by Weaver to describe engine with traction tires
• DPU - Distributed Power Unit
• DSS - Double Slip Switch
• DUT - Device Under Test
• DZ - Denver Zephyr
• E-unit - Electro-mechanical device used to reverse directions of Lionel trains
• EMC - Electro Motive Corporation - Progress Rail Services Corporation's (subsidiary of Caterpillar)
  Locomotive manufacturing division - Formerly EMD (See EMD)
• EMD - Electro Motive Division - General Motors Locomotive manufacturing division
  (Now Owned by Progress Rail Services Corporation) (See EMC)
  EMD E Units - EMD's Express Passenger Locomotives EA, E1, E2, E3, E4, E5, E6, E7, E8, & E9, Dual Diesel Engines (See Post by CBQ_Bill)
  EMD F Units = Freight Locomotives FT, F2, F3, F7, Single Diesel Engine (See Post by CBQ_Bill)
  EMD GP Units = General Purpose Locomotives, GP7, GP9, GP20, GP30, etc, Single Diesel Engine (See Post by CBQ_Bill)
  EMD SD Units = Special Duty Locomotives, Single Diesel Engine (See Post by CBQ_Bill)
• EOB - Engineer On Board - Replacement electronic drive system w/tach drive speed control system by Train America Studios (See TAS)
  Used by Sunset, Atlas & Weaver models. EOB used three Lionel drive and sound plug-in boards.
• ERR - Electric RailRoad Company
  Manufacturer of TMCC compatible electronics for upgrading Locomotives (Owned by Lionel)
• FM - Fairbanks Morse
• FRA - Federal Railroad Administration (U.S. Dept of Transportation)
• FRED - Flashing Rear End Device
• FS - For Sale
• FUBAR - Fouled Up Beyond All Repair
• FW&D - Fort Worth & Denver Rail Road (Subsidiary of CB&Q)
• FWIW - For What It's Worth
• FYI - For Your Information
• G2S - Goody 2 Shoes - Forum member who "Scolds" other forum members. Also - Forum member who fawned over the moderators
• G - G-Scale 1:22.5 Actual Size - G-Gauge = 1-3/4" Rail Spacing - Also referred to as Gauge 1 or One Gauge
• GE - General Electric
• GGD - Golden Gate Depot - Importer of Fine Scale Models From Asia
• GMTA - Great Minds Think Alike
• GOW - Grain of Wheat - Type of Light Bulb used in model trains
• GPZ - General Pershing Zerphy
• HITNC - How Is That Not Cool
• HMI - Human Machine Interface
• HHRC - Hand Held Remote Control
• HO - HO-Scale 1:87 Actual Size - 5/8" Rail Spacing (Half O)
• HooRoo - Ta Ta For Now - Bye (British and Australian term)
• H&St Joe - Hannibal & St Joseph Rail Road (Absorbed into CB&Q)
• HTT - Holier Than Thou - Better than everyone else
• IIRC - If I Recall Correctly
• IMHO - In My Humble opinion
• IMO - In My Opinion
• IPA - IsoPropyl Alcohol - Also India Pale Ale
• IOW - In Other Words
• IR - Infrared Sensor - Type of Sensor Used to Detect Train Location on a Layout
• IRB - Insulated Rail Block
• IRJ - Insulated Rail Joint
• ISO - International Standards Organization  - or also -  In Search Of
• ITS - Ives Train Society
• JLC - Johsua Lionel Cowen (August 25, 1877-September 8, 1965) - Founder Of Lionel
• JMHO - Just My Humble Opinion
• JMO - Just My Opinion
• K-Line - Manufacturer of Trains and Accessories (Maury Klein) (No Longer in Business - Part of K-Line is now Lionel)
  Also CB&Q Line between Keokuk IA and St Louis MO
• KCS - Kansas City Southern Rail Road
• KCZ - Kansas City Zephyr
• KISS - Keep It Simple Stupid (Simon to be polite)
• KTM - Katsumi Mokeiten Co., LTD., 3-10-5 Shimomeguro, Meguro-KU, Tokyo, Japan
  Japanese Manufacturer of Fine Brass Model Trains Used by U.S. Hobbies
• KW - Type of Lionel Transformer (Postwar) - Outputs 190 watts for two sets of trains
• Lash-Up - Tie Two or More Locomotives Together with Rope or String *Improper Terminology* See MU
• LCCA - Lionel Collectors Club of America
• LCD - Liquid Crystal Display
• LCS - Layout Control System - Lionel Legacy App to Control Your Layout from an Ipad
  (Could also be Legacy Control System)
• LED - Light Emitting Diode - Solid state replacement for incandescent light bulbs
  Used for Lighting Trains and Accessories Used for Lighting Trains and Accessories
• Legacy #990 - Lionel #6-14295 - Includes Lionel #991 Cab-2 Remote and #992 Command Base
• Legacy - Legacy Command Control System - Lionel 2nd Generation Control System (Also Controls TMCC)
• LI - Long Island (For all you (us) folks West of the NorthEast)
• Lionel - Manufacturer Of Model Trains and Accessories
• LIMA - Lima Locomotive Works an American Locomotive Manufacturer (1870s to 1950s)
• Live Steam - Refers to functional steam locomotives (live=under pressure, doing work) typically in scales larger than O.
• LHS - Local Hobby Shop
• LMAO - Laughing My *** Off
• LMFAO - Laughing My Fat *** Off (Also - Legacy Makes For Awesome Operating)
• LMGIFY - Let Me Google It For You
• LMGTFY - Let Me Google That For You
• LMK - Let Me Know
• LN - Like New
• LNC - Like New Condition
• LNL - Short for Lionel - Sometimes used as an abbreviation for Lionel
• LOTS - Lionel Operating Train Society
• LOL - Laughing Out Loud
• LOTF - Layout Of The Future
• LRRC - Lionel RailRoader Club - Now Part of the LCCA
• LSU - Legacy System Utility (Lionel)
• LTS - Local Train Store
• LUG - Legacy Users Group - Also Lego Users Group
• LVT - Low Voltage Transformer
• LW - Type of Lionel Transformer (Postwar) - Medium-sized - Outputs 125 watts for a single set of trains
• Ma&Pa - Maryland & Pennsylvania Railroad
• MAP - Minimum Advertised Pricing
• MAR - See Marx
• Marx - Manufacturer of toys including model trains and accessories (1934-1975)
  Founded by Louis Marx in 1919 (Often misidentified as "MAR" due to the letter configuration in the Marx logo)
• MCR - Machine Control Relay
• MESG - Modern Era Standard Gauge
• MHO - My Humble Opinion
• MM - Media Mail or Markdown Manager (used on ebay)
• MMI - Man Machine Interface
• MPC - Model Products Corporation (Subsidiary of General Mills Corporation) Purchased all rights to Lionel Trains in 1969
• MPC Era - Lionel products from 1969-1986 (See MPC)
• MRC - Model Rectifier Corporation (Manufacturer)
• MSRP - Manufacturer's Suggested Retail Price
• MTH - M.T.H. Electric Trains (Mike's Train House - Mike Wolf)
  Manufacturer Of Model Trains and Accessories (Most Frequent usage of MTH) (Also Midwestern Train Hobby, company that pre-dates Mike's, still in business; seldom used on OGR Forums)
• MTHRRC - MTH Rail Road Club
• MTZ - Mark Twain Zephyr
• MU - Multiple Unit Consist - Operating Two or More Locomotives Together as One Unit (As Real Trains do)
• N - N-Scale 1:160 Size - 3/8" Rail Spacing
• NASG - National Association of S Gaugers
• NC - Normally Closed (Contact Terminal on a Relay)
  (It's Normal State: Contact is Closed with no Power applied the Relay Coil - Opens with Relay Coil Powered)
• NIB - New In Box (Also see BNIB)
• NFG - Non Functional Gear (aka No ******* Good)
• NJHR - New Jersey Hi-Railers (NJ HiRailers)
• NKP - Nickel Plate Road (Railroad)
• NLA - No Longer Available
• NLOE - Nassau Lionel Operating Engineers (Model RR Club on Long Island that does special run cars each year)
• NMRA - National Model Railroad Association
• NO - Normally Open (Contact Terminal on a Relay)
  (It's Normal State: Contact is Open with no Power applied the Relay Coil - Closes with Relay Coil Powered)
• NOS - New Old Stock
• NS - Norfolk Southern Rail Road
• NP - Northern Pacific Rail Road (Now BNSF)
• NPR - National Public Radio (Often Incorrectly Used for Nickel Plate Road- See NKP)
• NYC - New York Central Rail Road (Now CSX)
• NZ - Nebraska Zephyr
• O - O-Scale 1:48 Size - Also O-Gauge 1-1/4" Outside Rail Spacing
• O27 - Compressed Size smaller than O-Scale but uses O-Gauge Track
• OB - Original Box
• OBTW - Oh, By The Way
• OFC - Oxygen Free Copper (as in layout wiring - much preferred for your layout over CCA)
• OGR - O-Gauge Railroading Magazine
• OMG - Oh My Gawd
• OP - Original Poster (Originator of Post or Thread)
• OSR - O Scale Railroading Magazine - Former Name Of OGR Magazine
• OST - O Scale Trains Magazine (For the 1:48 Scale Modeler)
• OSZ - Ozark State Zephyr
• OTC - Operating Track Controller (Also sometimes used as 'Over The Counter')
  For Activating Operating Track Sections with Lionel TMCC/Legacy
• OTG - On The Go
• OTOH - On The Other Hand
• OW5 - O Wide 5’ Gauge (Our 1-1/4 Rail Spacing) (In Jest - O Wrong 5’)
• PANS - Pretty Amazing New Stuff
• PCB - Printed Circuit Board
• PE - Polar Express (Also Pacific Electric - Electric Mass Transit System in Los Angeles, CA - No Longer in Business) (Can also be used for Photo Etch or Photo Etching)
• PFM - Pacific Fast Mail - Model Importer of Brass Trains - No Longer In Business
• PH - PowerHouse - Lionel PowerHouse Power Supply PH-180 (180 Watt) PH-135 (135 Watt) (See Brick)
• PIA - Pain In ***
• PITA - Pain In The ***
• PLC - Programmable Logic Controller
• PM - Private Message (Personal Message) - Dialogs on OGR Forums (For Premium Members Only)
• PO - Previous Owner or Post Office
• POS - Point Of Sale - (Also sometimes used to describe Trains or Accessories that are Not Behaving Properly)
• POTS - Plain Old Telephone Service or System (Just for Fun - We'll see if anyone notices?)
• PowerMaster - For Controlling Track Voltage with TMCC/Legacy System
• PRR - Pennsylvania Railroad (Now Norfolk Southern)
• PS-1 - ProtoSound - MTH 1st Generation Control & Sound System
  Installed In Locomotives designed for Conventional Operation
• PS-2 - ProtoSound 2 - MTH 2nd Generation Command Control & Sound System (DCS)
  Installed in locomotives - uses a battery
• PS-3 - ProtoSound 3 - MTH 3rd Generation Command Control & Sound System (DCS)
  Installed In Locomotives - No Battery; Improved Sound; LED Lighting
• PTC - Polymeric Positive Temperature Coefficient (Resettable Fuse used to protect Electronic Parts and Wiring)
  Also Positive Train Control (For Real Trains)
• PW - Post War (Lionel products from 1945-1969)
• PWC - Post War Classics - Lionel Reproduction Sets
• PZ - Pioneer Zephyr (Preserved at Museum of Science & Industry, Chicago, IL)
• Q - Sometimes used for CB&Q (See CB&Q)
• QC - Quality Control
• QO&KC = Quincy, Omaha, & Kansas City Rail Road (OK Line) (Hogback Road) (Absorbed by CB&Q)
• R/C - Radio Control
• R2LC - TMCC Receiver in TMCC engines
• R4LC - TMCC Receiver in TMCC engines
• RA - Return Authorization
• RMLI - The Railroad Museum of Long Island (which also does special run club cars each year)
• RDC - Rail Diesel Car
• RMT - Ready Made Trains (Manufacturer of Trains and Accessories) (Forum member Walter Matuch)
• ROFL - Rolling On Floor Laughing
• RoHS - Restriction of Use of Hazardous Substances (In Electronics)
• ROTFL - Rolling On The Floor Laughing
• ROTFLMAO - Rolling On The Floor Laughing My *** Off
• RR - Rail Road
• RRT - RR-Track Layout Design Software
• RTR - Ready To Run - (Not A Kit) - Or Ready To 'Retire' (my 'Run' days are long past, walking only)
• RW - Type of Lionel Transformer (Lionel postwar) - Medium-sized - Outputs 110 watts for a single set of trains
• SC-2 - Switch Controller - For Controlling Turnouts with Lionel TMCC/Legacy System
• SCARM - Simple Computer Aided Railway Modeller - Free Layout Design Software
• SGMA - Standard Gauge Module Association
• SHZ - Sam Houston Zephyr
• SI - Staten Island (Also for all you (us) folks West of the NorthEast)
• SMH - Shaking My Head
• SMT - Surface Mount Technology
• SNAFU - Situation Normal All Fouled Up
• SOP - Standard Operating Procedure
• SP - Southern Pacific Rail Road (Now Union Pacific)
• Standard Gauge - 2-1/8" Outside Rail Spacing (Prewar Lionel 3 Rail)
• Standard O - Scale Sized (1:48 Scale) - Used by Lionel for Their Scale Products
• SSZ - Silver Streak Zephyr
• SW - Type of Lionel Transformer (Postwar) Outputs 130 watts to run a single set of trains (Can also be used to refer to a Switch)
• Switch - Allows Train to Take an Alternate Route (Also See SW)
  Types = Right Hand (RH); Left Hand (LH); Wye; 3-way; Crossover; etc. - Sometimes called a Turnout
• TAS - Train America Studios - Youngstown, Ohio (no longer doing business)
• TBA - To Be Announced
• TBD - To Be Determined
• TCA - Train Collectors Association
• TCZ - Twin Cities Zephyr
• TEHO - To Each His/Her Own
• TIFWIW - Take It For What It's Worth
• TIU - Track Interface Unit - Part Of MTH DCS System (See DCS)
• TLA - Three Letter Acronym
• TLR - That Looks Right (scratch building term)
• TMCC - Trainmaster Command Control (1st Generation Lionel Control System)
• TMCC Direct LockOn - For Connecting PowerHouse Power Supplies Directly to Track with Lionel TMCC/Legacy
• Toby - Japanese Manufacturer of Brass Steam Locomotives
• TOOG - There's Only O Gauge or The Other O Gauge (MTH)
• TOS - Terms Of Service
• TPC - Track Power Controller (For Controlling Track Power with Lionel TMCC/Legacy System - 2 Versions: TPC-300 & TPC-400)
• Traditional - Smaller Sized (O-27) - Used by Lionel for their Postwar Remakes
• TRO - Test Run Only
• TTFN - Ta Ta For Now (British and Australian term)
• TTIUWP - This Thread Is Useless Without Photos
• TTOS - Toy Train Operating Society
• Turnout - Allows Train To Take an Alternate Route Also called a Switch (See Switch)
• TVS - Transient Voltage Suppressor - 1.5KE36CA For Old ZW's - 1.5KE33CA For Modern PH-180 Bricks
• TW - Type of Lionel Transformer (Postwar) - Outputs 175 watts for a single set of trains
• TY - Thank You
• TYVM - Thank You Very Much
• TZ - Texas Zephyr
• U - Old Generation Transformer Terminal Designation (Often Referring to Voltage Across Two Terminals as in AU, BU, CU etc.)
• uC - Micro Controller
• UCS - Lionel O-27 Track Section for Remote Uncoupling and Operating Car Activation
• uP - Micro Processor
• UP - Union Pacific Rail Road
• UPS - United Parcel Service
• USH - U.S. Hobbies
• USPS - United States Postal Service
• USRA - United States Railroad Association
• VAC - Volts AC
• VDC - Volts DC
• VL BB - Vision Line Big Boy (Top of the Line Lionel Big Boy Steam Engine (UP 4-8-8-4) for 2014)
• VW - Type of Lionel Transformer (Postwar 1948-1949) - 150 Watts for up to 4 Trains. Was Part of the 'Electronic' Set - Was replaced by and looks very much like a ZW - Could also be a Volkswagen
• WAG - Wild *** Guess (*** = think donkey)
• Wall Wart - Small Power Supply plugs into 120VAC Wall Outlet - Converts 120VAC to Lower Voltage. Can be either AC or DC.
• WBB - Williams By Bachmann (Bachmann Trains - Manufacturer of Trains and Accessories)
• WIP - Work in Progress
• WOMBAT - Waste Of Money, Brains, & Time
• WRT - With Respect To
• WTB - Want(ed) To Buy
• YMMV - Your Mileage May Vary
• Z4000 - Modern MTH Transformer
• Z - Type of Lionel Transformer (Prewar/Postwar) - Outputs 250 watts - Also Z-Scale - 1:220 Size - 1/2" Rail Spacing
• ZR - Zephyr Rocket
• ZW - Type of Lionel Transformer (Usually used to describe the Old Generation Type)
  These are Postwar (ZW-Pure Sine Wave 250 or 275 watts) and Modern Versions (ZW-C/ZW-L-Chopped Sine Wave)
• ZW-C - Type of Lionel Transformer (Lionel 6-32930) (Modern Type) (See ZW)
• ZW-L - Type of Lionel Transformer (Lionel 6-37921) (Modern Type) (See ZW)
• ZW-R - Also ZW (R) or ZW Model R - Type of Lionel Transformer (Old Generation) (uses 18V (#1445) indicator lamps instead of 6V (#51)

I'm no expert on the above list, so if you see something incorrectly listed, let me know.

In trying to keep the definitions as short as possible to make the list brief and more readable, some items have been edited. Hopefully no meanings were lost in editing. It might be worth a quick scan through this entire thread. Some of the suggestions include more detailed information that others have posted while suggesting some of these items.

This list has grown much larger than first anticipated! To all that have helped with this list, I wouldn't have known a lot of these without your help. Thanks To ALL!