This book constitutes the Proceedings of the second conference in the series 'Chemical Structures: The International Language of Chemistry' which was held at Leeuwenhorst Congress Centre, Noordwijkerhout, in the Netherlands, between June 3 and June 7, 1990. The conference was jointly sponsored by the Chemical Structure Association; the American Chemical Society Division of Chemical Information; the Royal Netherlands Chemical Society; and the Chemical Infor mation Groups of the Royal Society of Chemistry and the German Chemical Society. The purpose of the conference was to bring together experts and an international professional audience to discuss and to further basic and applied research and development in the processing, storage, retrieval, and use of chemical structures; to focus international attention on the importance of chemical information and the vital research being carried out in chemical information science; and to foster co operation among major chemical information organisations throughout the world. Subjects covered included structure-property correlations, spectral database systems, chemical nomenclature, generic structures, stereochemistry, substructure search systems, connection table formats, ring perception, information integration, three-dimensional substructure searching, similarity searching, and systems for handling chemical reaction information. All the papers were peer-reviewed or given by invited speakers. Many internationally recognised teams in the field of chemical structure handling are represented in the chapters of this book.