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The Chapman County Code for British Isles Counties

When the English Place Name Society was established in 1923, a series of abbreviations was produced for the English counties in existence at that time. Many of the abbreviations consisted of only one letter, some of two and a few of three letters. In 1973 the Society of Genealogists extended this system to cover other counties in the British Isles and published a list of abbreviations in the Genealogists’ Magazine, Vol 17 No 6. The Post Office and other authorities over the years used yet other standards to abbreviate county names. With the creation of new counties and the amalgamation of others in 1974, following the 1972 Local Government Act, the accepted, if not acceptable, contractions of county names multiplied. The Federation of Family History Societies founded in 1974 not only brought together many individuals and groups all having cause to frequently refer to county names within the British Isles, but also created interest among many thousands of others, each requiring to abbreviate a county name, and each appearing to choose a different system.


The advent of computers and the desirability for standardisation, to enable coding of results to be effected with the least confusion, led those of us working on these projects to consider a unified Three-Letter Coded system for each of the British Isles counties. Wherever possible I utilised the systems formerly proposed and used by the English Place Name Society and the Society of Genealogists as the basis for the present system; where necessary I extended the abbreviations from those systems to three letters in such a way that when these are truncated, the former system is regained. This principle has not always produced the most logical combination if those three letters were already allocated by a previous system to another county - and in two cases the Utopian idea was impossible. For example, Co, the 1923 abbreviation for Cornwall, would logically be extended to Cor, but as this had been allocated in 1973 to Cork, the code of Con was chosen; Sx, now being Ssx for Sussex and IOW in place of Wt for the Isle of Wight (to bring it into line with IOM for the Isle of Man), are exceptions to the general rules utilised to derive the present coded system for British Isles counties. As I also included the post-1974 counties for completeness, and to obviate further divergent applications in decades to come, other anticipated combinations of letters could not sensibly be utilised; for example, Cumberland, originally Cu, had to become Cul to prevent confusion with Cumbria which is coded as Cma.


Strictly speaking the three letters allocated to each county are a code element, and collectively the code elements form a particular code, in this case a three-letter or alpha-3 code; two letters for each code element would create an alpha-2 code. If three numerals had been chosen, the collective name would be a numeric-3 code; and if all three systems were to be considered, they constitute three codes.


As I was responsible for introducing the present County Code to some computerised work on records (specifically utilised by the Schools Council in a national project to introduce the use of computers in British schools in the early 1970s) the system was first drolly referred to as the Chapman County Code although, as stated above, I merely derived or adapted the abbreviations from those long established by others. However, this alliterative title adhered to the system and I offer it here to be used freely by all, in the hope that less confusion, combined with a greater acceleration of the recording and retrieving of geographical or historical data may be achieved. Nevertheless, a reference to this source by users will be helpful to readers of their work.


Colin R Chapman

June 1979.


Since the above was written, the Chapman County Code was used in 1987 by the British Standards Institution as the basis for the preparation of British Standard 6879 (revised in 1999), and by the International Standards Organisation in Geneva when publishing ISO 3166-2.

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