The document discusses the universe of knowledge and its key attributes. It defines the universe of knowledge as the totality of all knowledge that has survived until the present and will continue to be generated. It is described as infinite, multidimensional, dynamic and expanding in all directions over time. Segments within the universe of knowledge can merge or split off to form new segments. Subjects are composed of one or more segments and have their own characteristics, with subject names and headings sometimes changing over time.