UK ANO Schedule 7:
Private Pilot’s Licence (Aeroplanes)
(1) Subject to paragraph (2), the holder of a Private Pilot's Licence (Aeroplanes) is entitled to fly as pilot in command or co-pilot of an aeroplane of any of the types or classes specified or otherwise falling within an aircraft rating included in the licence.
(2) The holder may not:
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(c) unless the licence includes an instrument rating (aeroplane) or an instrument meteorological conditions rating (aeroplanes), fly as pilot in command of such an aeroplane:
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(iii) out of sight of the surface;