This is a preview of updates coming to the Technical Bulletin's website in early December 2025. Return to current site.
Read more about the modernization release schedule in this announcement.
Comment via the yellow feedback button in the lower right hand corner of the page. Contact the NLM Help Desk with any questions or concerns.

This is archived content.

Links may have become inactive over time. Visit Archive-It to find the original published layout.

NLM Classification 2013 Edition

Willis SR. NLM Classification 2013 Edition. NLM Tech Bull. 2013 May-Jun;(392):e1.

May 01, 2013 [posted]

The NLM Classification, available online at //www.nlm.nih.gov/class/, incorporates all additions and changes to the schedules and index from April 2012 through March 2013. The PDF version will be updated with 2013 classification data by the end of May 2013.

The QU (Biochemistry. Cell Biology and Genetics) schedule was the major area of focus for the 2013 edition. �

Background: With the 2005 edition of the NLM Classification, NLM established a new range of numbers in QU for cells (QU 300-400) and genetic concepts (QU 450-500). These topics were formerly scattered in various numbers in the Library of Congress general biology schedule, QH.� When the genetic terms were brought into the NLM schedule, they were split between the QU schedule and the QZ (Pathology) schedule (for clinical aspects).

With the 2013 edition:

Most genetic terms have been consolidated in the QU schedule
Several new class numbers were created in the QU schedule for genetic terms
Genetic terms currently classed in QZ deal with genetic causes of diseases and genetic testing
Animal genetic terms are classed in LC QH schedule (e.g.,� Animals, Genetically Modified is classed at QH 442.6)

In addition:

Some notes at the beginning of the QU schedule were added or changed. For example:
- Classify medical genetics in QZ 50 was changed to Classify genetic causes of disease in QZ 50.
- Classify viral genetics in QW 160 was added.
- Classify plant genetics in QK was added.
Some QU schedule outline headers were changed. For example:
- QU 145-220 Vitamins was changed to QU 145-220 Nutrition. Vitamins
Some QU class number captions and notes were revised to better reflect the scope of the number.�For example:
- At QU 34, the caption Biochemical phenomena (General or not elsewhere classified) was changed to Biochemical phenomena. Molecular biology (General or not elsewhere classified).
- At QU 84, the caption Sugar acids and their salts and esters (General or not elsewhere classified) was changed to Sugar acids. Sugar alcohols. Sugar phosphates (General or not elsewhere classified).
- At QU 130, the caption Inorganic substances (General or not elsewhere classified) was changed to Inorganic chemicals (General or not elsewhere classified).
- At QU 220, the caption Other vitamins was changed to Flavonoids.
- At QU 107, the note was added: Classify works on growth hormone at WK 515.
- At QU 375, the note was added: Classify physiology of specific cell with the cell.
- At QU 500, the note was added: Classify works on genetics in general in QU 450.

Class Numbers Added and Canceled

Thirty-two (32) new class numbers were added. �No class numbers were canceled.

**Class Numbers Added — 2013**
New Number	Class Name	Former Number in the Index
QU 45	Macromolecular substances (General or not elsewhere classified)	None
QU 55.95	Protein engineering	QU 450; QZ 52
QU 78	Glycosides	QU 75�
QU 81	Monosaccharides	QU 75�
QU 85.6	Lipid metabolism (General or not elsewhere classified)	QU 85�
QU 91	Prostaglandins	QU 90�
QU 102	Biological factors	None
QU 130.2	Metals (General or not elsewhere classified)	QU 130
QU 130.4	Minerals	QU 130
QU 145.3	Nutritional requirements	QU 145�
QU 145.7	Nutrition policy (Table G)	QU 145�
QU 145.72	[Nutrition policy] General coverage (Not Table G)	QU 145�
QU 460	Genomics	QU 58.5�
QU 465	Molecular medicine	None
QU 550	Genetic techniques (General or not elsewhere classified)	QU 450; QZ 52; WB 60
QU 550.5	Specific techniques, A-Z	None
QU 550.5.C4	Chromosome mapping	QU 450; QZ 52
QU 550.5.C5	Cloning	QU 450; QZ 52
QU 550.5.D6	DNA fingerprinting	QU 450
QU 550.5.G4	Gene expression profiling	QU 450; QZ 52
QU 550.5.G47	Genetic engineering	QU 450; QZ 52; WB 60
QU 550.5.M8	Mutagenicity tests	QU 450; QZ 52
QU 550.5.P6	Polymerase chain reaction	QU 450
QU 560	Genetic therapy	QZ 52
QV 56	[Pharmaceutical preparations] Adverse effects (General)	QZ 42
QV 58	Drug overdose. Prescription drug misuse	QZ 42
W 76.1	[Health manpower and services, distribution and characteristics] General coverage (Not Table G)	W 76
W 81	Medical tourism	None
WA 289	Consumer protection and product safety (General)	WA 288
WN 195	Optical imaging	None
WR 670	[Skin] Surgery	WR 650
WS 220	Palliative care. Terminal care	WS 200

Table G (Geographic Notations)

Changes were made to Table G (Geographic Notations):

One Table G number was added: GB1-- Balkan Peninsula

Other Changes to the Schedule

Changes were made to other class schedules. For example:

At QZ 42, Adverse effects of drugs was removed from the caption.
At QZ 50, Heredity. Medical genetics was changed to Heredity. Genetic causes of disease.
At QZ 52, Genetic techniques was changed to Genetic testing.
At WG 141.5.A3, Angiocardiography. Angioscopy was changed to Angiography. Angioscopy.
At WG 500, Radiography was removed from the caption.
The schedule outline WR 650-670 Therapy was added.
At WX 162, the caption was changed from Patient care planning. Progressive patient care. Long-term care to Hospital care. Patient care planning. Long-term care.
Instructional notes were added or modified to clarify classification practices as needed.� For example:
- A note was added to QY 95: Classify techniques associated with a specific type of cell with the cell.
- A note was added to WG 169: Classify works on cardiac anesthesia in WG 460.
Table G (geographic breakdown) is now permitted with W 76.

All index entries pertaining to the aforementioned schedule additions and changes were modified.

Changes to the Index

One hundred and eight (108) new index entries were created of which forty (40) are from the 2013 MeSH; �the remainder are MeSH terms from previous years. All main index headings are now linked to the 2013 vocabulary in the MeSH Browser.�

New Index Term

1 ABO Blood-Group System -- WH 420

2 Administration, Intravenous -- WB 354

3 Ageism

4 Arterial Pressure -- WG 106

5 Autacoids

6 Autophagy -- QU 375

7 Binge Drinking -- WM 274

8 Biochemical Processes -- QU 34

9 Biological Factors -- QU 102

10 Biomarkers, Pharmacological -- QV 745

11 Biometric Identification -- W 786

12 Boron Neutron Capture Therapy -- QZ 269

13 Butyrates -- QU 90

14 Cardiac Imaging Techniques -- WG 141

15 Cell Adhesion -- QU 375

16 Cell Lineage

17 Cell Physiological Processes -- QU 375

18 Chemical Safety

19 Chitosan -- QU 83

20 Community Integration

21 Controlled Substances -- QV 55-57

22 Coronary Angiography -- WG 141.5.A3

23 Deoxy Sugars -- QU 75

24 DNA Helicases -- QU 137

25 DNA, Fungal -- QW 180

26 Dermatologic Surgical Procedures -- WR 670

27 Device Approval -- WA 289

28 Diagnostic Test Approval -- WA 289

29 Drug Overdose

30 Elder Nutritional Physiological Phenomena -- WT 115

31 Exocytosis -- QU 375

32 Fertility Preservation

33 Food Quality

34 Gene Expression Regulation, Plant -- QK 981-981.7

35 Gene Regulatory Networks -- QU 470

36 Gene Targeting -- QU 550

37 Gene Transfer Techniques -- QU 550

38 Genes, BRCA1 -- WP 870

39 Genes, BRCA2 -- WP 870

40 Genocide

41 Genome -- QU 470

42 Genome, Bacterial -- QW 51

43 Genome, Plant -- QK 981-981.7

44 Genome, Viral -- QW 160

45 Geography, Medical -- WB 700-720

46 Health Impact Assessment -- W 84.4

47 Health Information Management

48 Health Information Systems

49 Health Services for Transgendered Persons -- WA 300-395

50 Homophobia -- HQ 76.4-.45

51 Immunoglobulins, Intravenous -- QW 601

52 Inappropriate Prescribing -- QV 748

53 Inflammation Mediators -- QV 247

54 Inventions

55 Ion Channel Gating -- QU 55.7

56 Macromolecular Substances

57 Magnetic Resonance Angiography

58 Mandibular Reconstruction -- WU 600-610

59 Maternal Death -- WQ 270

60 Mechanotransduction, Cellular -- QU 375

61 Medical Tourism

62 Molecular Medicine -- QU 465

63 Motivational Interviewing -- WM 55

64 Multienzyme Complexes -- QU 135

65 Mutagenesis, Insertional -- QU 55.95

66 Narrative Therapy -- WM 420.5.N3

67 Neurotology -- WV 21

68 Ochratoxins -- QW 630.5.M9

69 Optical Imaging -- WN 195

70 Organophosphate Poisoning -- QV 627

71 Organophosphonates -- QU 131

72 Pathologic Processes -- QZ 140

73 Pathology, Molecular -- QZ 50

74 Peptide Biosynthesis -- QU 68

75 Peroxisomes -- QU 350

76 Personal Narratives

77 Personal Narratives as Topic

78 Phosphorous Acids -- QV 138.P4

79 Physical Therapist Assistants -- WB 460

80 Prescription Drug Misuse

81 Prostate-Specific Antigen -- WJ 762

82 Proteome -- QU 460

83 Public Health Surveillance -- WA 950

84 RNA Interference -- QU 58.7

85 Racism -- HT 1503-1595.22

86 Radionuclide Ventriculography -- WG 141.5.R3

87 Receptor, Insulin -- WK 820

88 Receptors, Chemokine -- QU 55.7

89 Receptors, Cytoplasmic and Nuclear -- QU 55.2

90 Receptors, G-Protein-Coupled -- QU 55.7

91 Receptors, Serotonin -- QV 126

92 Retroelements -- QU 470

93 Rotator Cuff -- WE 810

94 Sexism -- HQ 1237-1237.5

95 Sialic Acids -- QU 84

96 Solid Waste -- WA 778-788

97 Somatomedins -- QU 107

98 Spinal Cord Stimulation

99 Telomerase -- QU 141

100 Telomere -- QU 470

101 Terminology as Topic -- W 15

102 Tobacco Products

103 Tomography, Optical -- WN 206

104 Transgendered Persons

105 Tumor Necrosis Factors

106 Vascular Access Devices -- WG 26

107 Waste Water -- WA 778-788

108 Water Resources -- WA 675-690

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

Aldosterone Antagonists was deleted as a main heading and made a cross reference to Mineralocorticoid Receptor Antagonists.
Jaundice, Hemolytic, formerly a cross reference to Anemia, Hemolytic, is now a cross reference to Jaundice.
Gene Therapy was changed to Genetic Therapy.
Balloon Dilation was deleted from the index.
Geography, Medical, formerly a cross reference to Geography, is now a main index heading.
The main index heading Handwashing was demoted to a cross reference and the cross reference, Hand Disinfection, became the main index heading.

To learn more about the NLM Classification see the Fact Sheet.