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11:27am on Monday, 16th December, 2013:

Recognition

Anecdote

Since 1963, vehicle registration numbers in the UK have followed one of three patterns.

First, they were 3 letters then 3 numbers then a letter that indicated the year in which they were registered, eg. ABC 123 D. They didn't use all the letters for years (Q and Z were reserved, for example), so in 1983 they ran out of letters for years. The format was then changed t0 start with the letter for the year, then 3 numbers, then 3 letters, eg. A 123 BCD. In both these cases, the first two letters of the three-letter group indicated the city of registration, so Hull was RH and KH. This was based on an even earlier system that didn't have any mention of the year encoded in it,

When they ran out of year numbers again, in 2001, the format changed entirely to the one we use today. First comes a letter indicating the region (E for Essex) then a letter indicating either nothing much or the town within the region in which they were registered (eg. K for Colchester, C having been taken by Chelmsford) then two numbers indicating the 6 months in which they were bought (eg. 07 for the first half of 2007 and 57 for the second half). These are followed by 3 letters to identify individual vehicles, giving something like EK07 ABC overall. As in previous systems, the year indicator doesn't line up with the actual year — 0 starts in March, 5 in September — so as to spread the time of year when people buy new cars.

From this, it should be clear that numberplates in Britain can be parsed. You can tell if something is a valid numberplate or not by its format. EK07 ABC would be valid, but EK0Z ABC wouldn't.

I paid for my parking at Luton Airport in advance, to save money. My car registration number starts EK07. When I entered the car park this morning, the numberplate-recognition software that analysed the photo taken at the barrier recorded it on the ticket as starting EK0Z. No numberplate in the UK starts EK0Z, I don't know that there are any numberplates in Europe that start EK0Z. That's what it decided it could see, though.

I'm going to have to use the intercom on the exit barrier when I leave. That'll be fun at midnight.




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Copyright © 2013 Richard Bartle (richard@mud.co.uk).