Hong Kong. (British Post Office in China). 1920. Registered envelope headed "Transmarina" Trading Company/ Shanghai Agency' addressed to The Hague, Holland bearing British Post Office in Shanghai SG 2, 2c green, SG 4, 6c orange (2), SG 5, 8c grey (2) and SG 6, 10c ultramarine tied by oval Registered/ Shanghai B.P.O. date stamp 'Ap 10 1920' with framed 'R/ Shanghai B.P.O./ No' hand-stamp on face, endorsed 'S.S. "Empress of Asia"/ via Canada' with Vancouver transit and s' Gravenhage arrival on reverse.