Library of Congress Classification System
Z - Library Science and Information Resources
| Z 4-115.5 | Books in General |
| Z 116-659 | Book Industries and Trade |
| Z 662-1000.5 | Libraries |
| Z 1001-8999 | Bibliography |
| ZA | Information Resources |
| Z | 4-115.5 | Books in General. |
| 4-8 | History of Books and Bookmaking | |
| 40-104.5 | Writing | |
| 41-42.5 | Autographs, Signatures | |
| 43-45 | Calligraphy | |
| 48 | Copying Processes | |
| 49-51.5 | Typewriting, Typewriters | |
| 52-52.5 | Word Processing | |
| 53-102 | Shorthand, Stenography, Phonography | |
| 102.5-104 | Cryptography | |
| 104.5 | Invisible Writing | |
| 105-115.5 | Paleography | |
| 116-659 | Book Industries and Trade. | |
| 116.A2 | Treatises on the Modern Printed Book | |
| 116.A3 | Book Design | |
| 116.A5-265 | Printing | |
| 124-228 | Printing: History | |
| 231-232 | Printers and Printing Establishments | |
| 234 | Medallic History of Printing, Tokens | |
| 235-236 | Printer's Marks, Mottoes, etc. | |
| 237 | Paper, Watermarks, etc. | |
| 239-239.9 | Books, Noteworthy as Examples of Fine Printing | |
| 240-241.5 | Incunabula, Block Books (including broadsides, playing cards) | |
| 243-264.5 | Practical Printing (including printing as a business, layout, paper and ink, machinery, type and type founding, electrotyping, typesetting, presswork) | |
| 265 | Reproduction of Books, Documents, etc. by Photography, Microphotography, etc. | |
| 266-276 | Bookbinding, Book Decoration | |
| 278-549 | Bookselling and Publishing | |
| 551-656 | Copyright | |
| 657-659 | Freedom of the Press, Censorship | |
| 662-1000.5 | Libraries | |
| 662-664 | Collected Works | |
| 665-718.8 | Library Science, Information Science | |
| 672 | Library Cooperation and Coordination | |
| 674.2-674.5 | Information Services, Information Centers | |
| 674.7-674.83 | Library Information Networks | |
| 675 | Classes of Libraries | |
| 678-678.88 | Library Administration and Organization, Constitution | |
| 678.89-678.892 | Library Service Agencies | |
| 678.9 | Automation | |
| 679-680 | Architecture and Planning of the Library (including space utilization, security, safety, lighting, etc.) | |
| 680.3-680.6 | Library Communication Systemd | |
| 681 | Photography and Other Methods of Reproduction in Library Science | |
| 681.5 | Trustees, Library Boards, Committees, etc. | |
| 682-682.3 | Personnel | |
| 683-683.5 | Finance, Insurance | |
| 684-685 | Supplies, Shelving, Bookstacks | |
| 686 | Branches, Delivery Stations, Bookmobiles | |
| 687-718.8 | The Collections, The Books | |
| 688 | Special Collections | |
| 688.5 | Processing | |
| 689 | Acquisition (selection, purchase, gifts, duplicates) | |
| 690 | Exchanges | |
| 691-692 | Special Classes of Materials (including manuscripts, maps, microforms, serials) | |
| 693-695.83 | Cataloging | |
| 695.85 | Library Handwriting | |
| 695.87 | Printing of Catalogs | |
| 695.9-695.94 | Indexing, Abstracting | |
| 695.95 | Alphabetizing, Filing | |
| 695.98 | Recataloging, Reclassification | |
| 696-697 | Classification and Notation | |
| 698 | Shelflisting, Author Notation | |
| 699-699.5 | Machine Methods of Information and Retrieval, Mechanized Bibliographic Control | |
| 700 | Bookbinding | |
| 701-701.5 | Injuries to Books, Book Hygiene | |
| 702 | Thefts and Losses of Books | |
| 703.5-703.6 | Moving, Disposition of Books on Shelves, etc. (including discarding, weeding) | |
| 711-711.92 | Reference Work | |
| 712-714 | Circulation, Loans, Charging Systems | |
| 716-716.1 | Library Extension, Library Commissions, Travelling Libraries | |
| 716.2-718.8 | Libraries in Relation to Special Topics | |
| 719-725 | Libraries (General) | |
| 719-871 | Library Reports of Individual Libraries, History, Statistics | |
| 881-980 | Library Catalogs and Bulletins | |
| 987-997.2 | Private Libraries, Book Collecting (including bibliophilism, bookplates) | |
| 998-1000.5 | Booksellers' Catalogs, Book Prices | |
| 1001-8999 | Bibliography. | |
| 1001 | Introductions to Bibliography, Documentation | |
| 1003-1003.5 | Choice of Books, Books and Reading | |
| 1011-1017 | General Bibliographies | |
| 1019-1033 | Special Classes of Books (including prohibited books, rare books, paperbacks, reprints) | |
| 1035-1035.9 | Best Books | |
| 1036 | Booksellers' General Catalogs of Modern Books | |
| 1037-1039 | Books for Special Clases of Persons, Institutions, etc. | |
| 1041-1121 | Anonyms and Pseudonyms | |
| 1201-4980 | National Bibliography | |
| 1201-1946 | America | |
| 1215-1363 | United States | |
| 1365-1401 | Canada, British North America | |
| 1411-1939 | Latin America | |
| 2000-2959 | Europe | |
| 3001-3496 | Asia | |
| 3501-3975 | Africa | |
| 4001-4980 | Australia, Oceania | |
| 5051-7999 | Subject Bibliography | |
| 8001-8999 | Personal Bibliography | |
| ZA | 3040-5185 | Information Resources |
| 3075-3080 | Research, How to Find Information | |
| 3150-3159 | Information Services, Information Centers | |
| 3201-4150 | Information Superhighway | |
| 4201-4251 | Internet | |
| 4375-4390 | Research, How to Use Networks, Online Services, etc. | |
| 4450-4460 | Databases | |
| 4550 | Motion Pictures, Video Recordings | |
| 4650 | Photographs | |
| 4750 | Sound Recordings | |
| 5050-5055 | Government Information | |
| 5070-5185 | Government Information in Specific Formats or Media |
To the Library of Congress Classification index
