MARC (CDS-Isis) exports data in ISO 2709 format but does not export the two indicator tags for MARC. The existing MARC import in Adlib, removes these indicator tags, and if these are not present, some bytes that contain valid data in CDS-Isis, will unfortunately be removed instead. To avoid this problem, use the separate import format (although comparable to the general MARC format): MARC CDS-Isis. This format retains the data at the position where the MARC format stores the indicators.