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NLM Classification 2017: Worldwide source of medical library classification

Scope of Revision for the 2018 Winter Edition


NLM Classification Updated in Two Phases

Starting with 2017, the NLM Classification moved from an annual spring update to twice-yearly updates.

The winter version, published in mid-to-late January, encompasses changes to the NLM Classification resulting from new and changed Medical Subject Headings (MeSH) terms as well as additional minor updates to the index and schedule.

The summer version, published in mid-to-late August, encompasses the ongoing systematic review of particular classification schedules and other miscellaneous updates.

The PDF version is published annually in the Fall.

Scope of Revision of the 2018 Winter Edition

The 2018 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 2018 vocabulary in the MeSH Browser. Additional minor updates were made to the Index and Schedules.

Summary Statistics for the 2018 Winter Edition

  • 93 index main headings added (86 from 2018 MeSH)
  • 114 index entries modified
  • 2 index headings deleted
  • 8 class numbers added
  • 1 new schedule range header added
  • 15 class number captions or notes modified
  • No class numbers canceled

Examples of Additions and Changes Based on MeSH 2018

Smoking Terminology

The majority of the new and modified smoking-related terms from MeSH 2018 were added to the Classification Index. Also, notes were added to relevant index entries to classify general works on smoking in WM 295. Specific substances are classified by the substance. For example, a general work on pipe smoking is classified in WM 295. A work on tobacco pipe smoking is classified with tobacco at WM 290.

Survival Terms

The new 2018 terms, Cancer Survivors and Survivorship were added to the Classification index. The caption at WM 167 was changed from “Psychological aspects of crime victims” to “Psychological aspects of survivors and survivorship.” An instructional note was added to “Classify works on HIV survivors in WC 503.7. Classify works on cancer survivors in QZ 260.” The new number QZ 260 was created for psychosocial aspects of neoplasms.

Sugars Terminology

Terminology and treeing of sugars was updated in 2018 MeSH vocabulary to better reflect their structure and properties. Likewise, adjustments were made to the NLM Classification. The caption at QU 81 was changed from “Monosaccharides” to “Sugars.” Some index terms classed at QU 83 Polysaccharides and derivatives, e.g., Dietary Sucrose, were reclassed at QU 81.

Changes to Main Index Headings

Numerous main index entries and cross references were modified to reflect changes in the MeSH vocabulary.

For example:

  • Beetles changed to Coleoptera.
  • Cell Aging changed to Cellular Senescence.
  • Electronic Cigarettes changed to Electronic Nicotine Delivery Systems.
  • The cross reference Cat Scratch Fever removed from Bartonella Infections and added to Cat-Scratch Disease.

Table G Changes


  • GG6—Ancient Greece
  • HE3—Ancient Egypt
  • JI5—Indochina


  • JI5 Indochina removed from obsolete Table G notations