We have partially sth. similar in Germany.
The first letter group (up to three characters) is the City or district: 'B' is Berlin, 'K' is Köln (Colgone), and 'DI', is 'Dieburg' which is my district.
The next letter group (up to two characters) is random, and then there is a random number from 1 to 9999.
My car has "DI-EH 1207'. And I have been having this plate now
since 22 years ...
No need for a new plate twice a year ...
(Only the 'TÜEV' (MOT in UK) sticker is renewed every two years).
BTW: My Diesel motorbike has 'DI-SL 15' which reads like 'DIeSeL, and '15' was the year when I bought it: 2015. ;-) I payed 12 € extra for this 'personalized' plate.