The London Borough of Hounslow (Hounslow Town Centre South) (Parking Places) Order 2023, see page 49.
"PART II - DESIGNATION OF PARKING PLACES
4. Designation of parking places
(1) The areas of highway as described in column 2 of Schedules 1, 2, 3, 4, 5, 6, 7 and 8 are designated as parking places.
(2) The limits of each parking place and the limits of each parking space, if marked within a parking place, shall be indicated on the highway by traffic signs of any size, colour and type prescribed or authorised under Section 64 of the Road Traffic Regulation Act 1984.
5. Manner of standing in a parking place
(1) Every vehicle left in a parking place shall stand so that every part of the vehicle is wholly within the limits of any parking space if marked, or within the limits of any parking place.
(2) Every vehicle left in a parking place in relation to which special provisions as to the manner of standing of a vehicle in that parking place is specified in column 3 of Schedules 1, 2, 3, 4, 5, 6, 7 and 8 shall stand so as to be in accordance with those provisions."