Keywords: marc 21 format for bibliographic data, series, cataloging.
this text presents the history and evolution of the fields 4xx - series statement fields of the marc 21 format for bibliographic data. recent change is discussed about the field 440 which was substituted by the fields 490 and 800-830. the application of the fields 490 and 800-830 is illustrated in the bibliographic records by examples mentioning their relation to the norms of the anglo-american cataloguing rules, 2nd edition, describing the impact of this change on bibliographic catalogs.