Class Z: Bibliography. Library Science. Information resources is a classification used by the Library of Congress Classification system. This page outlines the sub-classes of Class Z.^{[1] [2]}

4-115.5...............Books (General). Writing. Paleography

4-8..................History of books and bookmaking

40-104.5.............Writing

41-42.5.............Autographs. Signatures

43-45...............Calligraphy. Penmanship

48..................Duplicating processes. Copying services. Including mimeographing, multilithing

49-51.5.............Typewriters. Typewriting. Keyboards. Keyboarding

52-52.5.............Word processing

53-102..............Shorthand. Stenography. Phonography

102.5-104.5.........Cryptography. Cipher. Invisible writing

105-115.5............Manuscript. Paleography

116-659...............Book industries and trade

116.A2...............Treatises on the modern printed book

116.A3...............Book design

116.A5-265.5.........Printing

124-228.............History

231-234.............Printers and printing establishments

234................Medallic history of printing. Tokens

235-236.............Printer's marks, mottoes, etc.

237.................Paper. Watermarks, etc.

240-241.5...........Incunabula. Block books. Including broadsides, playing cards

242.9-264.5.........Practical printing. Including printing as a business, layout, paper and ink, machinery, type and type founding, electrotyping, desktop publishing, typesetting, presswork

265-265.5...........Representation or reproduction of books, documents, etc., by photography, microphotography, or other means

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..............Collections

665-718.8............Library science. Information science

668-669.7...........Library education. Research

672-Z672.13.........Library cooperation and coordination

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-Z678.93.......Automation

679-680.............Library buildings. Library architecture. Including planning, space utilization, security, safety, lighting, etc.

680.3-680.6.........Library communication systems

681-681.3...........Reproduction of library materials. Storage media of library materials

681.5-681.7.........Trustees. Library boards, committees, etc.

682-682.4...........Personnel

683-683.5...........Finance. Insurance

684-685.............Supplies. Shelving. Bookstacks

686.................Branches. Delivery stations. Bookmobiles

687-718.85..........The collections. The books

688................Special collections

688.5-688.6........Processing

689-689.8..........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

699.7..............Physical processing. Shelf preparation

700................Bookbinding

700.9-701.5........Physical parameters, preservation, conservation and restoration of books and other library materials

702................Thefts and losses of books and other library materials

703.5..............Stack management. Disposition of books on shelves, etc.

703.6..............Discarding. Weeding

711-711.95..........Public services. Reference services

712-714.............Circulation. Loans. Charging systems

716-716.15..........Library extension. Library commissions. Traveling libraries

716.2-718.85........Libraries in relation to special topics. Including libraries and community, libraries and television, children's libraries, libraries and students

719-723..............Libraries (General)

729-875..............Library reports. History. Statistics

881-977..............Library catalogs and bulletins

987-996.3............Book collecting. Including bibliophilism, bookplates

997-997.2............Private libraries

999-1000.5...........Booksellers' catalogs

1001-1121.............General Bibliography

1001.................Introduction to bibliography. Theory, philosophy, psychology. Bibliography. Documentation

1003-1003.5..........Choice of books. Books and reading. Book reviews

1003.8-1004..........Biography of bibliographers

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 classes of persons, institutions, etc.

1041-1107............Antonyms and pseudonyms

1201-4980.............National bibliography

1201-1946............America

1215-1363..........United States

1365-1401..........Canada. British North America

1411-1939..........Mexico. Central America. West Indies. South America

1975................Eastern Hemisphere

2000-2959...........Europe

3001-3496...........Asia

3501-3975...........Africa

4001-4980...........Australia. Oceania

5051-7999............Subject bibliography. Subjects arranged in alphabetical sequence

8001-8999............Personal bibliography. Names of individuals arranged in alphabetical sequence

3038-5190...........Information resources (General)

3150-3159..........Information services. Information centers

3201-3250..........Information superhighway

4050-4775..........Information in specific formats or media

4050-4480.........Electronic information resources

4150-4380........Computer network resources

4450-4460........Databases

4550-4575..........Motion pictures. Video recordings

4650-4675..........Pictures. Photographs

4750-4775..........Sound recordings

5049-5190...........Government information