Dynamism of Knowledge Organization, particularly its relation to UDC

[Abstract] This paper aims to explore the dynamism of Knowledge Organization from stability through extension to development, studying the theory and practice of concordance between different editions of UDC (Universal Decimal Classification), particularly in Hungary. Consideration is given to the principles, demands, changes and possibilities of UDC in the different Hungarian editions, evidencing general conclusions to the dynamism of Knowledge Organization. There were nine abridged editions of UDC since the Second World War including the last one in 2005, which was approximately ten years after the previous one. After the last Hungarian edition users, particularly librarians, waited for the concordance between two editions (1991 and 2005), because a similar concordance was also set up after the earlier two editions. The concordance can help librarians to use the new version whilst also maintaining and adapting the information from earlier editions. The last edition (2005) was based on the database of UDC MRF (UDC Master Reference File) at that time and it is hoped that it helps to set the concordance