Book excerpt: The quality declared seed system, as set out in the FAO Plant Production and Production Paper No. 117 (1993, ISBN 9251032785) has been widely used, particularly by those working in the field of emergency seed supply and as a source of practical information on seed standards for a range of crop species. The system provided an alternative for seed quality assurance, which was less demanding than full seed quality control systems. This publication sets out a revised version, prepared by an expert consultation, which offers a more explicit recognition of the role of national policies and the impact of some recent international obligations on seed provision and a clearer explanation on how quality declared seeds can accommodate local varieties. The list of crops now includes 92 species, of which 21 include open pollinated and hybrids and one includes also a synthetic variety. In making this update, FAO sought to improve seed supplies to farmers and thus to contribute to food security.