The Dewey Decimal Classification (DDC) is structured around ten main classes covering the entire world of knowledge; each main class is further structured into ten hierarchical divisions, each having ten divisions of increasing specificity. As a system of library classification the DDC is "arranged by discipline, not subject", so a topic like clothing is classed based on its disciplinary treatment (psychological influence of clothing at 155.95, customs associated with clothing at 391, and fashion design of clothing at 746.92) within the conceptual framework. The list below presents the ten main classes, hundred divisions, and thousand sections. Class 000 – Computer science, information and general works 000 Computer science, knowledge and systems 000 Computer science, information and general works 001 Knowledge 002 The book (writing, libraries, and book-related topics) 003 Systems 004 Data processing and computer science 005 Computer programming, programs and data 006 Special computer methods (e.g. AI, multimedia, VR) 007–009 [Unassigned] 010 Bibliographies 010 Bibliography 011 Bibliographies 012 Bibliographies of individuals 013 [Unassigned] 014 Bibliographies of anonymous and pseudonymous works 015 Bibliographies of works from specific places 016 Bibliographies of works on specific subjects 017 General subject catalogs 018 Catalogs arranged by author, date, etc. 019 Dictionary catalogs 020 Library and information sciences 020 Library and information sciences 021 Library relationships (with archives, information centers, etc.) 022 Administration of physical plant 023 Personnel management 024 [Unassigned] 025 Library operations 026 Libraries for specific subjects 027 General libraries 028 Reading and use of other information media 029 [Unassigned] 030 Encyclopedias and books of facts 030 General encyclopedic works 031 Encyclopedias in American English 032 Encyclopedias in English 033 Encyclopedias in other Germanic languages 034 Encyclopedias in French, Occitan, and Catalan 035 Encyclopedias in Italian, Romanian, and related languages 036 Encyclopedias in Spanish and Portuguese 037 Encyclopedias in Slavic languages 038 Encyclopedias in Scandinavian languages 039 Encyclopedias in other languages 040 Unassigned (formerly Biographies) 050 Magazines, journals and serials 050 General serial publications 051 Serials in American English 052 Serials in English 053 Serials in other Germanic languages 054 Serials in French, Occitan, and Catalan 055 Serials in Italian, Romanian, and related languages 056 Serials in Spanish and Portuguese 057 Serials in Slavic languages 058 Serials in Scandinavian languages 059 Serials in other languages 060 Associations, organizations and museums 060 General organizations and museum science 061 Organizations in North America 062 Organizations in British Isles; in England 063 Organizations in central