| 3142 | Preserved 4Cor unit owned by the SEG |
| 10096 | Trailer coach from Cor unit 3142 owned by the SEG |
| 11161 | Motor coach from Cor unit 3142 (originally in 3065) owned by the SEG |
| 11179 | Motor coach from Cor unit 3131 in National Railway Museum York |
| 11187 | Motor coach from Cor unit 3135 on long term loan to the SEG |
| 11201 | Motor coach from Cor unit 3142 owned by the SEG |
| 11825 | Trailer coach from Cor unit 3142 (originally in 3135) owned by the SEG |
| 12529 | Trailer coach from Buf unit 3085 (was part of the National Railway Museum collection). |
| 27 way | SR designed multiple unit system of 27 wires |
| 2Bil | 1930s built two car semi-fast or outer suburban emu, all withdrawn |
| 2EPB | 1950s built two car suburban emu, all withdrawn |
| 2Hal | 1930s built two car semi-fast or outer suburban emu, all withdrawn |
| 2Hap | 1950s built two car semi-fast or outer suburban emu, all withdrawn |
| 2Nol | 1930s built two car suburban emu, all withdrawn |
| 2Pan | two car parcels emu temporary conversion 1970s from 2Hal stock, all withdrawn |
| 2Pep | 1970s built two car prototype high density emu (basis for Class 508), all withdrawn |
| 2Sap | 1950s built two car semi-fast or outer suburban emu, all withdrawn |
| 2SL | 1920s built early two car suburban emu code South London, all withdrawn |
| 2Wim | 1920s built early two car suburban emu code Wimbledon, all withdrawn |
| 3Cep | three car express emu converted 1990s from 4Cep stock in service 1999 |
| 3Cop | three car express emu converted 1990s from 4Cig stock in service 1999 |
| 3Sub | 1920s built early three car suburban emu, all withdrawn |
| 3TC | 1960s built three car express trailer set used with 4Rep, all withdrawn |
| 4Bep | 1950s built four car express emu used with 4Cep heavily refurbished 1980s in service 1999 |
| 4Big | 1960s built four car express emu used with 4Cig in service 1999 |
| 4Buf | 1930s built four car express emu used with 4Cor, all withdrawn |
| 4Cap | four car semi-fast unit 1980s two 2Hap permanently coupled, all withdrawn |
| 4Cep | 1950s built four car express emu all units heavily refurbished 1980s in service 1999 |
| 4Cig | 1960s built four car express emu many units reformed 1980s and 1990s in service 1999 |
| 4COM | four car suburban emu 1980s recode of 4EPB, all withdrawn |
| 4Cor | 1930s built four car express emu, all withdrawn. Unit 3142 is preserved by the SEG |
| 4DD | 1940s built prototype four car double deck suburban emu, all withdrawn |
| 4EPB | 1950s built four car suburban emu, all withdrawn |
| 4Gri | 1930s built four car express emu converted from 4Res emu, all withdrawn |
| 4Lav | 1930s built four car semi-fast or outer suburban emu, all withdrawn |
| 4Tep | 1990s temporary formation refurbished Cep stock with unrefurbished Bep buffet |
| 4Pep | 1970s built four car prototype suburban emu, all withdrawn |
| 4Rep | 1960s built four car express Mk I based emu used with 4TC, all withdrawn |
| 4Res | 1930s built four car express emu, all withdrawn |
| 4SRKT | Diesel engine model used in EDL Class 73 and demu Class 205 and 207 |
| 4Sub | 1940s built four car suburban emu, all withdrawn |
| 4TC | 1960s built four car express Mk I based trailer set used with 4Rep, all withdrawn |
| 4Veg | four car semi-fast emu temporary 1970s 4Vep recode |
| 4Vep | 1960s built four car semi-fast or outer suburban Mk I based emu in service 1999 |
| 4Vop | four car semi-fast emu 1990s conversion from 4Vep in service 1999 |
| 5Bel | 1930s built five car all Pullman express emu, all withdrawn all cars survive 1999 |
| 5TCB | five car trailer set 1980s temporary 4TC reformation, all withdrawn |
| 5Wes | 1980s built Mk III based five car express emu in service 1999 |
| 6Cit | 1930s built six car express unit reformed into 6Pul/6Pan, all withdrawn |
| 6Cor | six car express unit 1960s temporary Pan/Cor stock, all withdrawn |
| 6Pan | 1930s built six car express unit used with 6Pul, all withdrawn |
| 6Pul | 1930s built six car express unit used with 6Pan, all withdrawn |
| 6TC | 1930s built six car push-pull test set withdrawn |
| 6YJXL | diesel engine model used in Class 74 electro-diesel now withdrawn |
| 8Dig | eight car express emu temporary 1990s Cig/Big reformations |
| 8LDA | diesel engine model used in Class 33 diesel locomotive now withdrawn |
| 8Mig | eight car express emu temporary 1980s Cig reformations |
| 8Vab | eight car express emu temporary 1970s Vep reformation |
| A | Ampere, unit measure of electrical current |
| A60 | LU train type used on East London line in the Southern Electric area |
| AC | alternating current |
| Adtranz | Train manufacturer |
| Alstom | Train manufacturer |
| Angel | A ROSCO |
| AWS | Automatic Warning System advising driver of status of certain signal types |
| Bel | stock type Brighton Belle |
| Bep | stock type Buffet electro-pneumatic (Kent Coast stock) BR Mk I body style with buffet |
| Big | stock type Buffet Brighton (1960s) BR Mk I body style with buffet |
| Bil | stock type bi-lavatory (1930s semi fast), all withdrawn |
| BoBo | electric or diesel locomotive with two powered two axle bogies |
| BR | British Rail brand name for British Railways British Railways nationalised railway from SR LMSR GWR LNER, predecessor to the current National Railways system |
| BR SR | British Railways Southern Region 1948 successor to Southern Railway |
| Brighton Belle | all Pullman express train that used to run between Brighton and London |
| Brush | electric traction equipment supplier |
| BTC | British Transport Commission 1950s body that used to oversee BR |
| BTH | British Thomson Houston former electric traction equipment supplier |
| Buf | stock type Buffet (1930s express), all withdrawn |
| C69 | LU train type used on District Line in Southern Electric area |
| Cap | Coastway Hap stock, all withdrawn |
| CCE | Chief Civil Engineer |
| CD | Central Division (of BR SR), now part of Southern Zone of Network Rail |
| Cep | Corridor electro-pneumatic (Kent Coast stock) BR Mk I body style |
| Cig | stock type Corridor Brighton (1960s) BR Mk I body style |
| Cit | stock type City (1930s express) |
| Class 33 | TOPS code 1960s built BoBo BR SR specified diesel electric locomotive |
| Class 37 | TOPS code 1960s built CoCo BR diesel electric freight and infrastructure locomotive |
| Class 47 | TOPS code 1960s built CoCo BR diesel electric general purpose locomotive |
| Class 50 | TOPS code 1960s built CoCo diesel electric locomotive used on Waterloo-Exeter service, all withdrawn |
| Class 66 | TOPS code EWS specified 1990s built CoCo freight diesel locomotive in service 1999 |
| Class 70 | TOPS code SR built 1940s electric locomotive, all withdrawn |
| Class 71 | TOPS code BR SR specified 1950s Kent Coast electric locomotive, all withdrawn |
| Class 73 | TOPS code BR SR specified 1960s electro-diesel locomotive |
| Class 74 | TOPS code 1960s rebuild of Class 71 into electro-diesel locomotive all withdrawn |
| Class 92 | TOPS code EWS operated 1990s built dual voltage CoCo electric locomotive for Channel Tunnel freight |
| Class 159 | TOPS code 1990s built three car semi-fast diesel unit used on Waterloo Exeter in service 1999 |
| Class 201 | TOPS code 1950s built 6S six car demu short underframe narrow body for Hastings line, all withdrawn |
| Class 202 | TOPS code 1950s built 6L six car demu long underframe narrow body for Hastings line, all withdrawn |
| Class 205 | TOPS code 1950s built 3H three car demu in service 1999 |
| Class 207 | TOPS code 1960s built 2D/3D two/three car demu in service 1999 |
| Class 313 | TOPS code 1970s three car high density unit on West London line in Southern Electric area |
| Class 319 | TOPS code 1990s built Mk III based four car outer suburban dual voltage Thameslink unit |
| Class 325 | TOPS code 1990s built four car Royal Mail dual voltage postal unit |
| Class 332 | TOPS code 1990s built four car express unit used on Heathrow Express |
| Class 365 | TOPS code 1990s built outer suburban dual voltage Networker unit |
| Class 373 | TOPS code 1990s built Eurostar set for Channel Tunnel passenger services |
| Class 375 | TOPS code CSE specified 1990s built four car main line unit |
| Class 401 | TOPS code 2Bil |
| Class 404 | TOPS code 4Cor |
| Class 405 | TOPS code 4Sub |
| Class 410 | TOPS code 4Bep unrefurbished |
| Class 411 | TOPS code 4Cep unrefurbished and refurbished; 3Cep |
| Class 412 | TOPS code 4Bep refurbished |
| Class 413 | TOPS code 4Cap |
| Class 414 | TOPS code 4Hap |
| Class 415 | TOPS code 4EPB |
| Class 416 | TOPS code 2EPB |
| Class 418 | TOPS code 2Sap |
| Class 419 | TOPS code MLV |
| Class 420 | TOPS code 4Big original configurations |
| Class 421 | TOPS code 4Cig; 3Com |
| Class 422 | TOPS code 4Big reformed configurations |
| Class 423 | TOPS code 4Vep and 4Vop |
| Class 424 | TOPS code projected Networker Classic rebuilding programme which has not actually taken place |
| Class 430 | TOPS code 4Rep before rebuild |
| Class 431 | TOPS code 4Rep after rebuild without buffet car |
| Class 438 | TOPS code 4TC |
| Class 442 | TOPS code 5Wes |
| Class 455 | TOPS code BR SR specified 1980s built Mk III based four car high density suburban unit |
| Class 456 | TOPS code BR SR specified 1980s built Mk III based two car high density suburban unit |
| Class 458 | TOPS code SWT specified outer suburban four car unit due to start in service in 2000 |
| Class 460 | TOPS code GEx Juniper series EMU |
| Class 465 | TOPS code NSE specified 1990s built four car Networker suburban unit |
| Class 466 | TOPS code NSE specified 1990s built two car Networker suburban unit |
| Class 488 | TOPS code BR Mk II 1970s built express trailer 1980s Gatwick Express stock |
| Class 489 | TOPS code GLV converted from Hap stock for 1980s Gatwick Express |
| Class 508 | TOPS code BR specified 1970s four car high density suburban unit, subsequently reduced to three car |
| Class 930 | TOPS code departmental unit |
| Class 931 | TOPS code departmental unit in service 1999 |
| Class 932 | TOPS code departmental unit |
| CMEE | Chief Mechanical and Electrical Engineer |
| CoCo | electric or diesel locomotive with two powered three axle bogies |
| COM | 4EPB unit with all compartment vehicles, all withdrawn |
| Connex South Central | TOC based on the former BR SR CD |
| Connex South East | TOC based on the former BR SR SED |
| Cop | Coastway open plan Cig conversion |
| Cor | Corridor (1930s express), all withdrawn |
| CP | Crompton Parkinson electric traction equipment supplier |
| CSC | Connex South Central |
| CSE | Connex South East |
| D78 | LU train type used in Southern Electric area on District line |
| DC | direct current |
| DD | Double Decker stock |
| de-icing | departmental unit used for removing ice and snow from third rail during adverse weather conditions |
| DEMU | diesel electric multiple unit |
| Dig | Dedicated Brighton temporary formation, classification has not ceased to exist |
| District Railway | predecessor of LU District Line |
| DL | diesel locomotive |
| Down | running line direction in general running away from London |
| E5001 | Preserved Class 71 electric locomotive owned by National Railway Museum, York |
| EDL | electro-diesel or dual powered locomotive |
| EE | English Electric supplier of most SR and BR SR electric traction equipment |
| EE507 | standard type of Southern electric traction motor made by English Electric |
| EE546 | alternate type of traction motor used in 1960s |
| electro-diesel | dual powered electric or diesel electric locomotive |
| Electrostar | catalogue name of emu produced by Alsthom |
| emu | electric multiple unit |
| EMU | electric multiple unit |
| English Electric | Supplier of most SR and BR SR electric traction equipment |
| Ep | electro-pneumatic braking system |
| EPB | electro pneumatic braking system |
| EPB | stock type Electro Pneumatic Brake |
| ER | Eastern Region (of British Railways) |
| EH | electric (train) heating |
| FL | Fast Line (track designation of higher speed line on multiple track route) |
| G315BZ | traction motor type supplied by GEC |
| GE | General Electric company of US (not connected with GEC of UK) |
| Gatwick Express | A train operating company |
| GEC | General Electric Company of UK (not connected with GE of US) |
| GEx | Gatwick Express |
| GLV | single car parcels and luggage emu used on Gatwick Express |
| Golden Arrow | Pullman service between Victoria and Folkestone |
| Gri | Griddle catering stock (1930s express), all withdrawn |
| GWR | Great Westerrn Railway |
| HA | CMEE drawing code of E5000 electric locomotive later Class 71 |
| HB | CMEE drawing code of E6100 electric locomotive later Class 74 |
| Hex | Heathrow Express |
| Hp | horsepower unit (imperial) measure of power |
| HSBC Rail (UK) | A ROSCO |
| Hz | Hertz unit measure of frequency |
| IC | Inter City |
| JA | CMEE drawing code of E6000 electric locomotive later Class 73/0 |
| JB | CMEE drawing code of E6000 electric locomotive later Class 73/1 |
| Juniper | total train supply concept by Alstom |
| KA | CMEE drawing code of D6500 electric locomotive later Class 33/0 |
| KB | CMEE drawing code of D6500 electric locomotive later Class 33/1 |
| kW | kilowatt unit (metric) measure of power |
| L&SWR | London & South Western Railway |
| Lav | Lavatory fitted stock, all withdrawn |
| LB&SCR | London Brighton & South Coast Railway |
| LBSCR | London Brighton & South Coast Railway |
| LGW | London Gatwick airport code |
| LHR | London Heathrow airport code |
| live rail | electric traction power supply contact rail |
| Live Rail | magazine of SEG |
| LL | Local Line defunct LSWR term for SL |
| LMR | London Midland Region (of British Railways) |
| LMSR | London Midland & Scottish Railway |
| LNER | London & North Eastern Railway |
| LSWR | London & South Western Railway |
| LT | London Transport |
| LU | London Underground |
| Mk I | 1950s BR standard passenger coach design with separate underframe and body |
| Mk II | 1960s BR standard passenger coach design of integral structure |
| Mk III | 1970s BR standard passenger coach design of integral structure and modular construction |
| ML | Main Line defunct WR term for FL |
| MLV | single car parcels and luggage emu (Kent Coast stock) |
| MR | Metropolitan Railway |
| MV | Metropolitan Vickers electric traction equipment supplier |
| MV339 | MV supplied traction motor type |
| Networker | High technology electric multiple unit specified by NSE |
| Network Rail | Organisation owning and operating the infrastructure used by TOCs |
| Night Ferry | One time boat train conveying through coaches to Continent withdraw 1970s |
| Nol | No Lavatory stock, all withdrawn |
| NRM | National Railway Museum, York |
| NSE | Network SouthEast |
| ONIX | Adtranz traction drive package |
| Pan | Pantry car stock, all withdrawn |
| Pep | Prototype electro pneumatic stock |
| Porterbrook | A ROSCO |
| Pul | Pullman car stock, all withdrawn |
| Railtrack | Former name of the organisation owning and operating the infrastructure used by TOCs |
| Rep | Restaurant electro pneumatic stock, all withdrawn |
| Res | Restaurant stock, all withdrawn |
| RL | Relief Line defunct WR term for SL |
| ROSCO | rolling stock leasing company |
| Sandite | substance sprayed on running rails to improve adhesion during falling leaves season |
| Sap | Second class only Hap stock, all withdrawn |
| Sarah Siddons | name of 1920s ex-Metropolitan Railway electric locomotive |
| SE&CR | South Eastern & Chatham Railway |
| SECR | South Eastern & Chatham Railway |
| SED | South Eastern Division (of BR SR) |
| SEG | Southern Electric Group |
| Silverlink | A train operating company |
| SL | Slow Line (track designation of lower speed line on multiple track route) |
| SL | South London stock |
| South West Trains | TOC based on former BR SR SWD |
| SR | Southern Railway 1923 merger of LSWR SECR LBSCR |
| SR | Southern Region (of British Railways) |
| Sub | Suburban stock |
| SWD | South Western Division (of BR SR) |
| SWT | South West Trains |
| TC | Trailer carriages, all withdrawn |
| TCB | Trailer carriages with buffet, all withdrawn |
| Thameslink | A train operating company |
| third rail | electric traction power supply contact rail |
| TL | Through Line defunct LSWR term for FL |
| Tm | traction motor |
| TOC | train operating company |
| TOPS | Total Operations Processing System operations central computer system |
| TOU | train operating unit (BR pre-privatisation) |
| Up | running line direction in general running towards London |
| V | Volt, unit measure of electrical potential |
| Veg | Vep Gatwick stock, classification no longer in existence |
| Vep | Vestibule electro pneumatic stock in service 1999 |
| Vop | Vep open plan stock |
| Wes | Wessex stock |
| Wim | Wimbledon stock, all withdrawn |
| WR | Western Region (of British Railways) |