.The validity of an order means here than a regularity in the course of social action brought about by custom or by given interests. If removal firms routinely advertise their services when new lettings are made then this regularity is dictated by their given interests. If a door to door salesman seeks out a specific group of customers on particular days of the month or of the week. Then that is either a familiar custom. Or alternatively a product of his particular interests(it is his turn to work a given patch)