Classification numbers from subclass ZA are now being assigned at the Library of Congress to newly cataloged materials. For works limited to information on a specific subject, see the subject Cf. Serials 3045 Congresses 3050 Directories. 3070 Juvenile works Research. 3080 Juvenile works Information services.
Information centers Including documentation centers, data libraries, bibiliographical centers, etc.
Clipping bureaus Cf. By place, A-Z Information superhighway 3201 Periodicals. Lists of resources 4150 General Resources of particular networks, online services, etc. Including works on how to use individual networks or online services Internet 4201 General works 4226 World Wide Web Cf. TK5105.888, Technology 4251.A-Z Particular online services, etc.