My son's Swiss-registered Volkswagen Multivan will be staying in the UK for some time - should it be registered with the DVLA?

My son currently lives in Bern and runs a Swiss-registered Volkswagen Multivan. He intends to return with his family to the UK in July, although will remain resident himself in Switzerland, commuting to...

90 limit

I frequently see commercial vehicles with a sticker declaring that "This vehicle is restricted to 56 mph by law". What law are they referring to, and if there isn't a 56 mph law, what's the point of the...