India. (Field Post Office). 1942. Registered Air Mail envelope endorsed 'O.H.M.S.' addressed to 'League of Nations, Geneva, Switzerland' bearing India SG 271b, 3a bright violet tied by 'Field Post Office No 12' date stamp '18/5' with provisional registration label and Base Army Post Office double ring on reverse '23rd May 42' and 'Army Base Office/Reg', routed via Egypt with 'Censorship/50' censor cachet and Fayid transit '25th May' with Geneva arrival '31st Aug' on reverse.