Iconclass is a classification of subjects, themes and motifs in Western art. It was developed and published in Holland, at the University of Leiden, with financial aid from both the Netherlands Organisation for the Advancement of Pure Research (Z. W.O.) and the Royal Netherlands Academy of Arts and Sciences.

Iconclass is used in a growing number of projects, whether computerised or not. One of these projects could be the Witt Library pilot project, discussed elsewhere in this issue of the Art Libraries Journal (pp. 27-31).

In this paper the classification as such is briefly explained, mainly with the help of two examples: scenes from the stories of St. Antony Abbot and Hercules. Information on the alphabetical index to the classification is given, mainly because this extensive part of Iconclass is something more than the usual index to a publication.

Applications of the classification are dealt with in diagrammatic form; one application, the Iconclass bibliography, is discussed in greater detail.