Ukd serves to catalog texts depending on the fields and disciplines of science, culture and human activity. The modern Ukd design clearly divides the fields, which is the most important element in the structure of the publication and the cataloging process, hence the colorful, large dividers on mass dyed paper. Clear labeling of domain symbols and the arrangement of these symbols within paragraphs allows you to quickly understand how these symbols are created.

The National Library of Poland acts as the central library of the country and is one of the most important cultural institutions in Poland. Its mission is to protect national heritage preserved in the form of handwritten, printed, electronic, recorded sound and audiovisual documents. The primary task of the National Library of Poland is to acquire, store and permanently archive the intellectual output of Poles, including the works of citizens living on Polish soil, the most important foreign works, and publications related to Poland and published abroad.