There are no references to Jewish people in the series.
Starting in 1521, the Dubrovnik Republic paid customs duties at a flat rate (i.e. in advance) to the Ottomans on behalf of Dubrovnik merchants who traded in the European part of the Ottoman Empire. This customs duty was called giumruch (Turkish: gümrük) and amounted to 100,000 akches (aspers) per year. Special customs officers, so-called giumruchi, would travel around the trading settlements and colonies to collect this duty giumruch. The series consists of books that were kept based on the reports done by these officials and each book contains lists of merchants and the amounts of customs duties these merchants paid, or were obliged to pay, in several ten-year periods of the 16th and the 17th centuries.