Nice Pic of a Swallow

[Dutch-Ulster rep]

I'm not from the UK, so I wonder - when did all this transferring of number plates from car to car start? I ask because on one hand people here always lament the transferring of original number plates, but on the other hand, whenever an old(er) picture appears, everyone seems to be convinced it shows the original number plate. They than seem to think they can glean all sorts of information from the number plate, whereas it could just as well be transferred from an other car. In other words, maybe it is indeed a VW number plate dated from before 1929 that he had lying around from an earlier car? It all depends on when this habit of swapping of number plates started, doesn't it. If it started early in the history of number plates, one can never be certain an old(er) picture does indeed shows the 'original' number plate - unless, i guess, there is some other piece of evidence that accompanies it, such as the registration or the logbook?