This series contains maps, plans, architectural and technical drawings, extracted from records of various government departments, in series in the department references ADM, AH, AIR, AVIA, BJ, BT, CAB, CO, COPY, CUST, DEFE, DO, ED, F, FO, HLG, HO, INF, IR, LAB, LAR, MEPO, MH, MINT, MT, NSC, OS, POWE, PRO, RAIL, RG, T, WO, WORK and ZLIB. There is no common subject matter.
As far as possible, places depicted on maps or drawings are identified in catalogue descriptions by the names given on, or contemporary with, the documents themselves, although spellings have been modernised and standardised to facilitate searching. Where there has been a significant change to the name of a place or that of the political or geographical area in which it is situated, the current name is usually given in brackets after the name taken from the document. If it has not been possible to identify the place named, the name given on the map or drawing is noted in inverted commas. If no place is named, and the location cannot be identified, this is noted explicitly in the description.
Places now in the London area, but outside the City of London, are identified according to the county or borough in which they were situated at the date when the map or plan was produced. 'London' or 'London:' followed by a borough name, is used in describing material produced during the period of the London County Council (1899-1965) or the Greater London Council and successor authorities (1965 to date). Where appropriate to facilitate searching, the current inner London borough is also noted in brackets. For places which remained in Essex, Middlesex, Surrey and Kent until 1965 only the original county, and not the current outer London borough, is noted.