The Chapman codes are a set of three-letter codes adopted to identify counties and other areas of the British Isles. They were compiled by Dr Colin Chapman in the 1970s in connection with his work on computerised records, in particular for the Schools Council's national project to introduce the use of computers in British schools in the early 1970, and the "Chapman County Codes" as they became known swiftly spread. Today they are most widely used in genealogy.
Chapman's achievement was to produce a single set of codes in a consistent system, capable of use universally. It was not the first set of county abbreviations by any means; the English Place Name Society produced a series of abbreviations in 1923 for counties in England but a mixed system of one-letter, two-letter and three-letter abbreviations. The Society of Genealogists published a list of abbreviations for the whole of the British Isles in 1973.
In the 1970s Dr Chapman studied the systems published by the English Place Name Society and the Society of Genealogists and determined that a consistent system required a set of three-letter codes. Some of these were the same three-letter code used by the Society of Genealogists but two-letter and one-letter codes were expanded.
Chapman's system covered not only the counties but certain other areas, such as the Isle of Wight (IOW), the City of London (LON) and each of the three Ridings of Yorkshire. He also adopted codes for administrative counties and for the local government areas invented by the 1972 Local Government Act.
The Chapman codes are now incorporated in national and international standards for abbreviations: BS 6879 and the ISO 3166-2:GB, to identify historic counties and administrative divisions past and present in the United Kingdom, the Republic of Ireland, the Isle of Man and the Channel Islands.
The Historic Counties Standard codes
The Historic Counties Trust in developing the Historic Counties Standard adopted a separate system of codes similar to the Chapman codes. The Chapman codes were rejected since they are used, in accordance with the published British Standard, to stand in for names which might have several different applications, which is to say that the code "CAM" stands for "Cambridgeshire" but may be used for the county of that name or for the administrative area which uses the same name but which has a very different extent. Therefore, a new set of codes was required to represent the historic counties only, and which codes were required not to overlap with any Chapman code.
The Historic Counties Trust codes cover all the counties of the United Kingdom. The system was developed by Dr Peter Boyce.
The table below gives the Chapman code for each county, together with the Historic Counties Standard code and Historic Counties Standard number.
Counties of the United Kingdom
|IOM||Isle of Man|
Counties of the Republic of Ireland
|IOW||Isle of Wight|
|LND||London, City of|
|ERY||Yorkshire, East Riding|
|NRY||Yorkshire, North Riding|
|WRY||Yorkshire, West Riding|
- Genealogists Magazine, Vol 17 No 6
- Colin Chapman on the Chapman County Codes (Lochin Publishing)