[David Herbert]

For those not familiar with the 1950s series of British army registrations, the letters were assigned in alphabetical order but with some codes reserved or not used. So BC is later than BB and EA is later than both. It is possible that FL was reserved for BATUS but I suspect not. The letter pairs did not refer to particular dates but most followed on from each other so do actualy help to date vehicles. Within each letter pair vehicles were allocated numbers in blocks at the time of purchase contract. A block of numbers could start at 00XX01 and end anywhere, so there might well be a completely different vehicle type starting at say 02XX01 (leaving 200 possible vehicles in the first block) and the next block could start at 42XX01 (leaving 4000 possible vehicles in the second block). The blocks were almost always bigger than the actual number of vehicles delivered but also it was possible for identical vehicles to be registered in more than one letter pair - for example FV434 REME fitters vehicles with ED and FA registrations.

So the Land Rover 101 is over 4600 registrations later than the 2 1/2 ton trucks and there could be all sorts of other things in between (and also gaps)

While on the subject, letter pairs starting with X, Y or Z were for renumbered vehicles that had had WW2 style registrations and the RAF had letter pairs starting with A.

Once a vehicle received a registration of this style it kept it for life, regardless of conversions etc. So Humber Pigs kept the registration of the 1ton trucks that they were converted from for example.

In the 1970s it got much more complicated...

David