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Call Numbers: Home

Understanding and using Call Numbers

Call Number Systems used at UToledo Libraries

Most of the UToledo Libraries book collections are shelved according to Library of Congress (LC) Call Numbers. Each letter designates a broad subject area and is further divided into two letter subjects, then by number. The last part of the call number identifies a particular book within a specific subject area. A full outline of the system is available at the Library of Congress website.

A General Works

  • AE Encyclopedias
  • AY Yearbooks & Almanacs

B Philosophy/Psychology/Religion

  • B-BD Philosophy
  • BF Psychology
  • BL-BX Religion

C: History: Related Fields

  • CC Archaeology
  • CT Biography

D History (except N. & S. American)
E American History
F Local History & Non-US History of North & South America

G Geography/Anthropology/Recreation

  • G-GF Geography
  • GN Anthropology
  • GV Recreation

H Social Sciences

  • HA Statistics
  • HB-HJ Economics, Business, & Finance
  • HM-HX Sociology

J Political Science

  • JK United States
  • JX International Law

K Law

  • KFO Ohio Law

L Education
M Music
N Fine Arts
P Languages and Literature

  • PA Classical Languages & Literature
  • PE English Language
  • PN Literary History & Film
  • PQ Romance Languages Literature
  • PR English Literature
  • PS American Literature

Q Science

  • QA Mathematics & Computers
  • QB Astronomy
  • QC Physics
  • QD Chemistry
  • QE Geology
  • QH Natural History & General Biology
  • QK Botany
  • QL Zoology
  • QR Microbiology

R Medicine

  • RM Pharmacology
  • RS Pharmacy
  • RT Nursing

S Agriculture
T Technology

  • TA Civil Engineering
  • TJ Mechanical Engineering
  • TK Electrical Engineering
  • TP Chemical Engineering

U Military Science
V Naval Science
Z Bibliographies and Library Science.

Books at the Mulford Health Science library are shelved according to the National Library of Medicine (NLM) Call Numbers. Each two-letter code designates a broad subject area, and numbers within each area identify a more specific subject area. Note that NLM numbers do not overlap with Library of Congress (LC) numbers, so a collection could have both numbering systems, with LC being used for non-medical areas. A full outline of the system is available at the NLM website.

Preclinical Sciences:
    QS Human Anatomy
    QT Physiology
    QU Biochemistry. Cell Biology and Genetics
    QV Pharmacology
    QW Microbiology and Immunology
    QX Parasitology
    QY Clinical Pathology
    QZ Pathology

Medicine and Related Subjects:
    W General Medicine. Health Professions
    WA Public Health
    WB Practice of Medicine
    WC Communicable Diseases
    WD Disorders of Systemic, Metabolic or Environmental Origin, etc.
    WE Musculoskeletal System
    WF Respiratory System
    WG Cardiovascular System
    WH Hemic and Lymphatic Systems
    WI Digestive System
    WJ Urogenital System
    WK Endocrine System
    WL Nervous System
    WM Psychiatry
    WN Radiology. Diagnostic Imaging
    WO Surgery
    WP Gynecology
    WQ Obstetrics
    WR Dermatology
    WS Pediatrics
    WT Geriatrics. Chronic Disease
    WU Dentistry. Oral Surgery
    WV Otolaryngology
    WW Ophthalmology
    WX Hospitals and Other Health Facilities
    WY Nursing
    WZ History of Medicine. Medical Miscellany

The Government Documents are arranged by Superintendent of Documents (or SuDoc) numbers. The letters correspond to government agencies. When reading SuDoc numbers, remember that the number after the colon should be read as a whole number... C 2:10 is followed by C 2:11, not C 2:105, for example. A full explanation is available on the Federal Depository Library Program website.

Common Superintendent of Documents Divisions

  • A Department of Agriculture
  • Commerce Department
    • C3 Census Bureau
    • C21 Patent and Trademark Office
  • CC Federal Communications Commission
  • CR Civil Rights
  • CS Civil Service Commission
  • D Defense Department
  • E Department of Energy
  • ED Department of Education
  • EP Environmental Protection Agency
  • FT Federal Trade Commission
  • GA General Accounting Commission
  • GS General Services Administration
  • HE Health and Human Services
  • NH Department of Housing and Urban Development
  • I Department of the Interior
  • IC Interstate Commerce Commission
  • J Justice Department
  • Labor Department
    • L2 Labor Statistics
  • P Postal Service
  • PrEx Executive Office of the President
  • S State Department
  • SBA Small Business Administration
  • Treasury Department
    • T22 Internal Revenue Service
  • TD Transportation Department
  • VA Veterans Administration
  • X Congressional Record
  • Y3 Congressional Commissions, Committees, Boards
  • Y4 Congressional Hearings

Search the Catalog by Call Number

Using Call Numbers

Call numbers are very useful things. Each book in the library has a unique call number, and call numbers help group books together that are on the same subject. Every call number has several parts, and finding a book on the shelf is just a matter of reading each part in the right order.

Read the first line in alphabetical order: A single letter (Q) comes before two letters (QD). QD
Read the second line as a whole number:
1, 2, 13, 76, 76.76, 76.8, 80, 137, 200, 1999, 2000, etc.
The third line is a combination of a letter and numbers. Find the letter first, then read the number as a decimal, looking at each digit in turn from left to right.
.01, .1, .19, .20, .75, .755, .76
Finally, some books have the publication year as the very last line. 1986