As far as I know it's anything over 7.5 tonnes that can't park on housing estates and a transit flat bed like above would he under so they can get away with it, there's a few area in my borough where they have them either for scrapping cars or banger racing and nothing can be done as I'm aware as it's the same as taking a company van home.
I've seen them and the ones with the spec lifts parked up aswell for national recovery companies aswell and nothing happens unfortunately