Cataloguing rules for old books have evolved since the 1961 Paris Principles. New information aids now allow for an enhancement of the catalogue. The FRBR model, the XML format also offer new possibilities. The authors of the article emphasize the contribution of digitization to the cataloguer's tasks: edition description, control and standardization of access, indications of the particularities of copies. They conclude by the need to work as a network and to conduct deliberation at national and international level.