"While it was conceived in 1952, the first published edition of this classification system appeared in 1962. Since then, its use has spread widely throughout the United States, Israel and other parts of the Jewish world. Libraries of all kinds, in synagogues and community centers, in Hebrew schools, on college campuses and in research institutions, have adopted the scheme and worked with it. As a result, a body of experience in applying the system to all these diverse institutions developed, clearly demonstrating the need for minimal changes in the system from time to time while reaffirming the utility of its basic organizing principles. Meanwhile, the intervening years have been full of events deeply significant in contemporary Jewish history, all of which need to be reflected in an up-to-date classification scheme."