| Letter | Destination Area |
| A | London Kings Cross (Up Main Line). |
| B | London Kings Cross area. |
| D | Doncaster/Leeds area. |
| E | Eastern Region. |
| F | Special Services. |
| G | Special Services. |
| J | Sheffield area. |
| L | Anglia Region. |
| M | London Midland Region. |
| N | Newcastle/Teeside/York area. |
| O | Southern Region. |
| P | Peterborough area. |
| S | Scottish Region. |
| V | Western Region. |
| X | Special Services. |
| Z | Special Services. |
| Rep. Numbers | Numbers | Destination Area |
| 2L02 - 2L30 | Even | To Anglia Region. |
| 2M01 - 2M29 | Odd | To London Midland Region via Luffenham. |
| 2E02 - 2E30 | Even | From London Midland Region via Luffenham. |
| 2E01 - 2E29 | Odd | From Anglia Region. |
| 2E01 - 2E29 | Odd | From London Midland Region via Hebden Bridge. |
| 2M02 - 2M30 | Even | To London Midland Region via Hebden Bridge. |
| 2M31 - 2M59 | Odd | To London Midland Region via Petteril Bridge Junction or via Dore. |
| 2E32 - 2E60 | Even | From London Midland Region via Petteril Bridge Junction or via Dore. |
| 2E31 - 2E59 | Odd | From London Midland Region via Newark Castle. |
| 2M32 - 2M60 | Even | To London Midland Region via Newark Castle. |
| 2M61 - 2M89 | Odd | To London Midland Region via Skipton. |
| 2E62 - 2E90 | Even | From London Midland Region via Skipton. |
| 2E61 - 2E89 | Odd | From London Midland Region via Bingham or via Diggle. |
| 2M62 - 2M90 | Even | To London Midland Region via Bingham or via Diggle. |
| Letter | Destination Area |
| C | Moorgate/London Kings Cross - Finsbury Park or Hornsey EMU Depot. |
| F | Moorgate - Letchworth via Hertford North (2F00-2F49). |
| H | Moorgate - Hertford North (2H01-2H79). |
| J |
Letchford (via Hertford North) and Hertford North - Moorgate. ECS from and via Hertford North - Hornsey EMU Depot. |
| K |
Welwyn Garden City - Moorgate. ECS from and via Welwyn Garden City - Hornsey EMU Depot. |
| R | London Kings Cross - Hitchin/Letchworth/Royston via Welwyn Garden City. |
| V | Moorgate - Welwyn Garden City. |
| W | London Kings Cross - Hertford North/Letchworth/Royston. |
| Y | ECS Ferme Park - Bounds Green - Hornsey Carriage Sidings. |