1 - LIBRARY SCIENCE
1a - Serials
1c - Documentation
1d - Archives
1e - Standardization

2 - THE PROFESSION
2a - Education

3 - BIBLIOGRAPHY
For bibliographic description see 15a; for analytical bibliography see 20
3a - Bibliographies, reference books
On professional subjects only
3b - Bibliographic control

4 - LIBRARY CATALOGUES
4a - Serials
4b - Manuscripts, rare books
4c - Specific subjects

5 - LIBRARY ADMINISTRATION AND ORGANIZATION

6 - AUTOMATION

7 - LIBRARY POLICY
7a - Libraries and society
7b - Co-operation and systems

8 - LAW AND LEGISLATION
8a - State legislation
8b - Regional legislation

9 - GENERAL LIBRARIES
9a - National and State libraries
9b - Other conservation and research libraries
9c - Public libraries
9d - Church libraries
9h - Library history

10 - SPECIAL LIBRARIES AND SERVICES
10a - Children libraries
10b - School libraries
10c - University libraries
10d - Company libraries
10e - Music libraries
10f - Libraries for special users
Including disabled, aged, migrants, prisoners
10g - Local and community services
10h - Other special libraries

11 - BUILDINGS AND FURNITURE

12 - COLLECTION DEVELOPMENT

13 - SPECIAL MATERIALS
13a - Microforms
13b - Theses
13c - Serials
13d - Grey literature
13e - Audiovisual materials
Including non-book materials
13f - Printed music
13g - Cartographic materials
13h - Electronic publications
13l - Antiquarian books
13m - Manuscripts

14 - PRESERVATION AND CONSERVATION
14a - Restoration

15 - CATALOGUING
15a - Bibliographic description
15b - Author cataloguing
15c - Serials cataloguing
15d - Grey literature cataloguing
15e - Non-book materials cataloguing
15f - Printed music cataloguing
15g - Cartographic materials cataloguing
15h - Electronic publications cataloguing
15l - Antiquarian books cataloguing
15m - Manuscripts cataloguing

16 - SUBJECT INDEXING
16a - Alphabetical subject cataloguing
16b - Thesauri
16c - Classification
16d - Electronic information

17 - PUBLIC SERVICES
17a - Reference and information work
17b - Use of electronic information
17c - Document delivery

18 - READING
18a - Youth and children literature

19 - PUBLISHING
19a - Book trade
19b - Statistics
19c - Directories
19d - Publishing history
19e - Individual publishers and printers

20 - HISTORY OF THE BOOK
Including analytical bibliography
20a - Printing
20b - Decoration and illustration
20c - Bookbinding
20d - Private libraries