The Thesaurus database will include all illustrations of ancient artefacts contained in the source works of the 17th and 18th centuries included in the project's work plan. Also included are all illustrations of artefacts in the source works that were obviously considered antique by the respective author. In addition, any prototypes of the illustrations, whether explicitly named or deduced during data entry, are also included in the database.
Thesaurus records are also created for antique and non-antique artefacts. Objects that have survived to the present day and can be identified with certainty are taken into account, as are those whose identification has not (yet) been successful and those that have been demonstrably destroyed or lost, but also those whose (former) existence is rather questionable.
Within the Thesaurus, Internal links with the attributes "depicts" or "is depicted in" relate the visual sources and the artefacts to each other.
If the dependence of an image on an earlier illustration of the same artefact can be clearly demonstrated, e.g. by an explicit source citation, or can be deduced on the basis of certain external features, the corresponding records are linked with the attribute "has copy" or "is copy of".
Several copies of the same edition of a work that have survived in different contexts are linked to each other with the attribute "is duplicate of".
Different stages in the production process of prints, especially proofs, are linked to each other and to the final published work with the attributes "is preparatory for" or "is based on".
More general references from one database object to another, which cannot be assigned to the types mentioned above, but which could contribute to a better understanding of the object, are provided with the attribute "in relation to".
Links to external resources provide direct access to further information. These include the complete digitised version of the source work, from which usually only the illustrations are listed in the Thesaurus; the reference record for the object in the collection database of the owning institution; records for the same object in other digital repositories such as in iDAI.objects Arachne, in the Census or in epigraphic databases.