It appears the prefix 'N' on the narrow gauge codes may not have been applied at the start of the narrow gauge running, there is evidence in offical documentation of codes without the prefix. This would have caused confusion in official correspondence, and it seems that the codes were altered to include the prefix around the time of the official opening of the first narrow gauge railway. The exact date of the recoding is unknown.

The fixed wheel stock was relettered away from "A", "B", "C", "D" grouping and placed into the unused letters "X", "Y" and "Z".

Bogie stock was originally represented with double letters which represented a double 'capacity'. They were relettered into single letter classing.
Note: "BEBE" was altered in 1907 to "BE".
Guard vans were changed from "D" to "C".
Mail vans were changed from "E" to "D", "S" added for mail sorting (originally mail sorting was either "S" or "MS").

'C' type corridor cars were changed to "L".
'E' type express cars were changed from "VE" to "E" (dropping the "V" for vestibule).
Guard vans were changed from "D" to "C".
Mail vans were changed from "E" to "D", "S" added for mail sorting.

"C" hearse vans were changed to "J".
"F" (small fixed wheel) and "F^F" (larger fixed wheel) horseboxs were changed to "F".
"F^FF" (bogie) were changed to "FF".
"WS" workmans sleepers were changed to "W" (fixed weel) and "WW" (bogie).

Suburban cars were rationalised and simplified to: D - Driver's compartment, M - Motor car (with driver's compartment), and T - Trailer.
Also, instead of having both 1st and 2nd class of ecah type, they were simplified to: M - 1st class, T and D - 2nd class

NG freight vans were recoded to follow the 1910 recoding.

About 6000 "I" wagons with various capacities from 8 to 20 LT were split by capacity:
"I" with a dual capacity of 11/16 LT were changed to "IA".
"I" with a capacity of 8, 10 and 11 LT were changed to "IB".
"I" with a capacity of 20 LT were changed to "IY".

"IG" with a capacity of 16 LT were changed to "I".

Some vans had previously been fitted with high speed, passenger type bogies and were used in passenger train service, their code not reflecting the maximum speed.
In 1956, to segregate freight vehicles that had passenger speed capability, they were recoded with a "P".
Note: The mail baggage "TT" vans that were recoded "TP" only ran in service for about twelve months before being recoded "BP".
Note: "ZP" vans were only authorised for a maximum speed of 60mph

Some wagons and vans had previously been modified for use as breakdown vans, but retained their previous codes and numbers.
In 1956, they were recoded to allow those in non revenue service to be easily identified.

To provide rollingstock for the service to Sydney after the 1962 standardisation project, a number of carriages were converted to standard gauge.
Because the codes would have overlapped with existing New South Railways codes, the cars were reclassed.
The new codes were an approximation of appropriate NSW carriage codes, but with a "V" prefix to indicate the Victorian Railways as the owner.
Note: 1st Class AW became 2nd Class VFW.
NSW carriage codes Non-NSW carriage codes

All states were required to provide a percentage of bogies and parts to other states based on the percentage of bogie exchange vehicles in the interstate 'pool'.
To reduce the cost of providing bogies and equipment, VR/Vicrail reduce the number of bogie exchange ("X") wagons in service by reclassing some wagon to non interchange bogies ("F").

(See National Code)
New standard 'Australia wide' lettering system.
Note: New "ELX" wagons were issued to traffic as "VOCX" in 1978.
First Letter: Used to describe the owner, V - Victoria
Second Letter: Indicated the type of vehicle
Third Letter: Used to segregate the different types with the same second letter. Some were grouped by age, some by traffic type
Fourth Letter: Indicated speed and bogie exchange capability plus bogie type if required
Note: Stock in the "P" group were coded with the last two letters "PY".

Guards vans were recoded to follow the 1979 recoding.
"VVxx" (V-Victoria, V-van, x-age and x-bogie/speed).

Between 1985 & 1990 service stock were recoded to follow the 1979 recoding.
Until this time, they were either still using their old pre-national code or grouped into other vehicle types (eg VHWA ballast hopper).
"VZxx" (V-Victoria, Z-departmental, x-type and x-bogie/speed).

"Y" was mistakenly adopted for high speed, non interchange bogies, this was changed to letter "F" to indicate the same thing.

Steel crrying wagons were all regrouped, Coil Steel as "xCxx" and Slab Steel as "xKxx".