Synopsis ANALYTICO-SYNTHETIC CLASSIFICATION- the brain-child of S.R. Ranganathan has brought about an intellectual revolution in the theory and methodology of library classification by generating new ideas. By his vast erudition and deeper research in the Universe of Subjects, Ranganathan applied a postulation approach to classification based on the concept of facet analysis, Phase Analysis, Sector Analysis and Zone Analysis. His enquiry into the concept of fundamental Categories as well as the Analytico-Synthetic quality associated with it, the use of different connecting symbols as in the Meccano apparatus for constructing expressive class numbers for subjects of any depth, the versality of Notation, the analysis of Rounds and Levels, the formation and sharpening of Isolates through various devices, the introduction of the novel concepts of Specals, Systems, Speciators, and Environment Constituents has systematized the whole study of classification into principles, rules and canons. These new methodologies in classification invented as a part of Colon Classification have not only lifted practical classification form mere guess work to scientific methodology but also form an important theme in international conferences. The present work discusses in details the unique methodologies of Ranganathan as used in CC-7. The concepts of Primary Basic Subjects and Non -Primary Basic Subjects have also been discussed at length.