Maps published by the Ordnance Survey of Great Britain.
Old Series, New Series, and Third Edition one-inch maps of England and Wales are in ZOS 9, ZOS 10 and ZOS 11 respectively; one-inch maps of Scotland and Ireland are in ZOS 13 and ZOS 14 respectively. Six-inch maps of England and Wales are in ZOS 12; six-inch maps of Ireland are in ZOS 15. National Grid six-inch maps, some incorporating revisions undertaken between 1948 and 1957, are in ZOS 1. Five-foot maps of London and environs are in ZOS 8
History maps are in ZOS 5. Tithe survey index maps are in ZOS 6. A facsimile of the Down Survey of Ireland, 1655 to 1658, is in ZOS 7
Maps overprinted with thematic information are in ZOS 4. Administrative Area Maps are in ZOS 2. Maps overprinted with military grids, in use before and during the Second World War, are in ZOS 3
The Public Record Office is not an official place of deposit for Ordnance Survey maps. Since Ordnance Survey maps are publications, their normal place of deposit is the British Library and the other legal deposit libraries, viz. Cambridge University Library, the Bodleian Library Oxford, the National Library of Wales, the National Library of Scotland, and Trinity College Dublin.
Because the Ordnance Survey maps are among the most satisfactory land maps produced officially, they have often been used by central and local government departments and agencies for their own specific purposes. For that reason, most OS maps in the custody of the PRO have at some time been working maps, and contain information from the departments that used them. The maps in these series, on the other hand, have not been used.