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NLM Classification 2017: Worldwide source of medical library classification

Scope of Revision of the 2019 Winter Edition


The 2019 MeSH (Medical Subject Headings) vocabulary was evaluated for inclusion in the Classification index. Several additions and changes were made to the Index and Schedules based on this review. All main index headings are now linked to the 2019 vocabulary in the MeSH Browser. Additional minor updates were made to the Index and Schedules.

Summary Statistics for the 2019 Winter Edition

  • 74 index main headings added (61 from 2019 MeSH)
  • 172 index entries modified
  • 11 index headings deleted
  • 16 class numbers added [see Class Numbers Added and Canceled (Current Edition)]
  • 55 class number captions or notes modified
  • 1 new schedule range header added
  • 3 schedule range headers modified
  • No class numbers canceled

Examples of Additions and Changes Based on MeSH 2019


Publication Type (PTs) and As Topic Terms

  • Several PTs in the index were modified to reflect the 2019 MeSH changes, e.g., Diaries was changed to Diary; the new corresponding topical heading, Diaries as Topic was added
  • New PTs that were formerly topical MeSH in the index were deleted and the new 2019 Publication Types were added, e.g., the topical heading Catalog, Union was deleted and the new PT Catalogs, Union was added
  • Sub-indexes (SIs) under existing PTs in the index were removed and the new specific PT was added, e.g., the SI Chemical was removed from the PT Dictionary and the new PT Dictionary, Chemical was added

Additions/Changes to the Schedules as the Result of New MeSH Additions to the Index

  • Child Labor: new numbers created: WA 327 Child labor (Table G) and WA 327.1 General coverage (Not Table G)
  • Drug Development: Caption at QV 745 changed from Drug design. Drug discovery to the broader Drug development. Drug discovery
  • Insulin Secretion: New class number created: WK 802 Physiology. Biochemistry. Several insulin terms removed
  • Insurance, Vision: new numbers created: W 273 (Table G) and W 273.1 General coverage (Not Table G)
  • Internet Access: Header before W 74 changed from Medical Economics to: Access to Health Information and Healthcare. Medical Economics; New number inserted after the header: W 70 Access to health information

Systematic Review of Sexuality Concepts

A systematic review of sexuality terms and related concepts was conducted to reclassify some of these concepts from LC classification to NLM’s schedule.

  • New header added before WM 607: Sexual Dysfunctions. Gender Identity. Sexual Behavior
  • 7 new class numbers added:
    • WM 617          Gender identity. Transsexualism. Transgender persons
    • WM 620          Sexuality. Sexual behavior (General or not elsewhere classified)
    • WM 620.5       Specific topics, A-Z [indented under WM 620]
    • WM 620.5.B5   Bisexuality. Bisexual persons [indented under WM 620.5]
    • WM 620.5.H4   Heterosexuality. Heterosexual persons [indented under WM 620.5]
    • WM 620.5.H6   Homosexuality. Homosexual persons [indented under WM 620.5]
    • WZ 80.5.S4     Sexual and gender minorities [Indented under WZ 80.5]
  • 7 class numbers modified
  • 6 index terms added
    • Coitus Interruptus WJ 710
    • Gender Dysphoria WM 617
    • Premature Ejaculation WJ 709
    • Reproductive Physiological Phenomena WQ 205
    • Sexual Abstinence WM 620
    • Sexual Health WM 620
  • 2 index terms deleted
  • Several index terms modified

Table G (Geographic Notation) Additions

Two notations were added to the M--International Agencies section

  • MM4--Médecins sans frontieres (Association
  • MW5—World Health Assembly

A note was added to A--United States (Federal Government) for clarification: This section is used for serial publications only.


2019 Summer Edition

The 2019 summer version will be published in mid-to-late August 2019. It will encompass the systematic review of the QW (Microbiology. Immunology) and (QX Parasitology) schedules and other miscellaneous updates. The PDF version will be published annually in the fall.