Crosby et al. (1976) subdivided the New Zealand mainland (North, South, and Stewart Islands, plus nearby inshore islands) into 29 approximately equalsized areas, and defined two-letter codes for each. The codes and boundary definitions for these areas were provided on a separate, large map enclosed with the journal issue. These areas were modified from the areas used as weather forecast districts by the New Zealand Meteorological Service, and their main purpose was to facilitate the arrangement, retrieval, and documentation of specimens in the New Zealand Arthropod Collection (NZAC). The codes have subsequently been used in other collections, for computer databases, and in publications as a convenient way of categorising specimen data. The New Zealand Journal of Zoology paper is provided here as an attachment to this record and is available for download.