Prints from the early period of letterpress printing (incunables) are seperately stored in libraries and generally reviewed and explored seperately, since modern rules of cataloguing are not suitable for publications, that originate from a time when rules of bookdesign were not commonly agreed upon. In the Ratsschulbibliothek of Zwickau incunables were never stored seperately, so that, before an incunable could be included in the catalogue, its whereabouts in the stock had to be determined . Through this catalogue libraries and interested researchers get a clear picture of the amount and content of the collection of early prints, as well as information about their provenance and heritage.