1. IOR/M/3/455 Reference (shelfmark): IOR/M/3/455 Title: B2259/38; Defence : confidential instructions to masters and wireless operators in British merchant ships Scope & Content: Secret Call Sign and Instructions for the Master and W/T Operators London, 1938 Collection Area: India Office Records and Private Papers Languages: English Date Range: 28 Apr 1938-9 Jan 1942 Extent: 1 file