Lecture Notes aim to report new developments -quickly, informally, and at a high level.The following describes criteria and procedures for multi-author volumes.For convenience we refer throughout to "proceedings" irrespective of whether the papers were presented at a meeting.The editors of a volume are strongly advised to inform contributors about these points at an early stage.§ 1.One (or more) expert participant(s) should act as the scientific editor(s) of the volume.They select the papers which are suitable (cf.§ §2-S) for inclusion in the proceedings, and have them individually refereed (as for ajoumal).It should not be assumed that the published proceedings must reflect conference events in their entirety.The series editors will normally not interfere with the editing of a particular proceedings volume -except in fairly obvious cases, or on technical matters, such as described in § §2-S.The names of the scientific editors appear on the cover and title-page of the volume.§2.The proceedings should be reasonably homogeneous i.e. concerned with a limited and well defined area.Papers that are essentially unrelated to this central topic should be excluded.One or two longer survey articles on recent developments in the field are often very useful additions.A detailed introduction on the subject of the congress is desirable.§3.The final set of manuscripts should have at least 100 pages and preferably not exceed a total of 400 pages.Keeping the size below this bound should be achieved by stricter selection of articles and NOT by imposing an upper limit on the length of the individual papers.§4.The contributions should be of a high mathematical standard and of current interest.