FAQ
NLM's Subject Headings Differ in LocatorPlus and OCLC

Question: Why are NLM's LocatorPlus subject headings different from NLM's subject headings found in OCLC records?

Answer:

- with 1999 MeSH and the implementation of the Voyager Integrated Library System, the Cataloging Section moved to harmonize its practices for subject heading content and structure with NLM's indexing practices
- these changes are intended to facilitate cross-file searching and enhance retrieval by assuring that the same terms produce like results for articles, books, nonprint materials, electronic resources, etc.
- NLM's subject headings in LocatorPlus records follow the indexing pattern:
- - the 650 contains only main headings or main headings and topical subheadings
- - the geographic qualifiers are in the 651 field and publicaton types (PTs, aka form divisions) are in the 655 field
- when NLM distributes these records in the MARC format, a program recombines the appropriate headings
- detailed instructions on how to combine a 650 with a 651 or a 655 are given in Application of MeSH for Medical Catalogers at http://www.nlm.nih.gov/tsd/cataloging/catmesh.html

Related Questions:: Cataloging and Bibliographic Questions; LocatorPlus Questions

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http://www.nlm.nih.gov/services/cat_meshoclc.html

Last updated: 06 May 2004
First published: 01 January 1998
Metadata| Permanence level: Permanence Not Guaranteed

FAQNLM's Subject Headings Differ in LocatorPlus and OCLC