An international system of protected area categories In 1994, after several decades of development, IUCN – The Conservation Union and the World Conservation Monitoring Centre (WCMC) published Guidelines for Protected Area Management Categories, in English, French and Spanish1 – guidance on the only widely recognised international system of protected area categories. The IUCN categories were originally developed as a ‘common language’, to help communications and reporting on protected areas. In the decade since publication in 1994, several things have happened to stretch and perhaps sometimes distort this original aim. First, the number of protected areas has continued to increase rapidly – with the global total now exceeding 100,000. The pressures on these precious places have increased too. So the questions relating to the categories cover many more issues, and refer to a far larger area, than in 1994. Secondly, in the absence of any other international framework, the IUCN categories have been used in ways that their original architects did not fully foresee; for instance as the basis for legislation or for attempting to control land use within existing protected areas. As the uses of the categories have expanded, so too has the intensity with which they have been scrutinised. What began as a simple classification exercise has assumed far greater political importance.