SEZNAM DĚL NEDOSTUPNÝCH NA TRHU.

The article deals with the List of Out-of-Commerce Works (Seznam děl nedostupných na trhu – SDNNT) which has been maintained by the National Library of Czech Republic. The list is based on the records of the Union Catalogue of the Czech Republic for monographic and periodical publications published in the Czech Republic.The records in the SDNNT are continuously harmonised with their original resource in case of deduplication. The article also introduces the reader to SDNNT, a web-based application developed in 2022 that supports not only the management of the list, but also facilitates cooperation with digital libraries and enables right holders to optout their works. While the original version of the list required manual verification of market availability by librarians, this procedure is now automated [ABSTRACT FROM AUTHOR]