Few birdwatchers are systematists or have any real knowledge of taxonomy and the reasons behind scientific nomenclature. We all, however, make constant use of classification: even non-ornithologists can recognise a duck as a duck or a thrush as a thrush; at a more advanced level, identifications often start with a generic determination such as, 'There's a Sylvia', later refined to become, 'It's a Lesser Whitethroat'. Thus, even those who might not be able to define systematics or taxonomy are recognising the basic importance of a natural classification system. Nevertheless, the sequence in which birds are listed and their scientific names are, sadly, of relatively little interest to the majority of British and Irish birdwatchers. Convenience is of most importance and, for that reason, change is not welcome. The names and sequence employed in The Handbook (1938-41) remained in use by British ornithologists for 13 years, until the publication in 1952 of the British Ornithologists' Union's Check-list of the Birds of Great Britain and Ireland. Since then, the familiar 'Wetmore order' of the 1952 list has remained relatively unchanged, although dozens of new species have been 'slotted in', sometimes in rather arbitrary positions. In 1971, the BOU published The Status of Birds in Britain and Ireland, which, with slight modifications, employed a combination of the nomenclature of Dr Charles Vaurie's The Birds of the Palearctic Fauna (1959, 1965) and, after much argument, the sequence of J. L. Peters's Check-list of Birds of the World (1931-70).