South Africa. (Natal). 1916. Registered South Africa postal stationery envelope 4d blue cancelled by boxed 'Prisoner of War' cachet in violet with framed 'R/ Natal/ Maritzburg' and circular Registered/ Pietermaritzburg with 'Passed by Censor' hand-stamp in violet and circular 'Post Free/ P.C./ Prisoner of War' on face with 'Opened by Censor' label, addressed to Hamburg, Germany but intercepted by the British with framed instructional 'Hostile Countries Censor/ Salisbury House, London' in violet on face.