Editorials, devotional literature, poems, and book reviews are excluded, but review essays are included. Beginning in 1995, festschriften will be included in the machine readable form of the service, though not in the printed version. In addition to its coverage of current periodicals, an ongoing retrospective conversion has as its goal the conversion of ZID into machine-readable form back to 1975. At present the computerized index goes back to 1994. The entries are classified into 130 categories.
Indexing is provided by numerous access points, including broad keywords.
A more refined keyword structure is being planned. Although ZID competes with comprehensive indexes such as Religion Indexes, IBZ, the Arts and Humanities Citation Index and Francis, its selection of periodicals matches most closely the holdings of German theological and religious studies collections.