China. (French Naval Detachment in China). 1939. Envelope written from Tien-Tsin endorsed 'F.M.', addressed to Dap Cau, Tonkin cancelled with circular 'Corps D' Occupation de Chine/ Le Vaguemestre' with 'Postal Militaire' label tied by circular 'A/1' cachet with oval 'Ouvert/ Par/ L' Autorite Militaire' hand-stamp on face with Hanoi and Dap Cau arrival '7th Oct 39'. Scarce censor item sent internally between Tien-Tsin and Tonkin very early in WW2.