Where can you legally stay overnight in a camper?

[tight fart]

Without having mr plod knocking on the door asking you to move on?
Friends have told me different things such as anywhere you can legally park in the new forest, & Dartmoor.
A lot of car parks will say no overnight etc but if not mentioned is that considered ok?
And is the law different in Scotland?

[tight fart]

BGARK said:

This website, wild camping, free pub stopovers and all the standard stuff, I have used all over Europe:

www.searchforsites.co.uk

Click view by map an instantly see whats around you..

Booked a pub stopover for Saturday night off of that very site tonight!