Every VD 17 record has a unique number including the prefix VD 17 (e.g., VD17 14:013691X). This form should be used in every citation of a VD 17 item. The number preceding the colon indicates the library code for the origin of the title record. The VD 17 number can be searched either by a free text search or by selecting the search key [VDN] VD17-number.
Due to later amendments or additions, some title records may have been deleted, e.g. when titles have been identified as duplicate copies. In those cases, however, the relevant catalogue entries contain a note regarding the VD 17 number of the deleted record. The former VD 17 number is still searchable.