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ENGL 2001 Nursing Communication

Research guide for ENGL 2001 nursing communication

Understanding LC Call Numbers

The LC Classification System is similar to Dewey, as it is also subject based, classifying and arranging items by the subject matter involved. Each piece of a LC call number is a classification that begins broad, getting more specific to the subject of the book with each number. Decimals also help the number get more specific.

However, the LC call numbers begin with letters, followed by various letters and/or number combinations. Each letter stands for a general subject area. By breaking items into 21 subject areas rather than the 10 of Dewey, the LC classification system allows libraries to classify and arrange larger collections.

LSU Libraries uses LC call numbers for most of it's books.


  • The first letter of the LC call number is the general subject area. The LC system is broken into 21 primary classes, or general subject areas, represented by letters.
A General Works J Political Science R Medicine
B Philosophy. Psychology. Religion K Law S Agriculture
C Auxiliary Sciences of History L Education T Technology
D World History M Music and Books on Music U Military Science
E,F History of the Americas N Fine Arts V Naval Science
G Geography. Anthropology. Recreation P Language and Literature Z Bibliography. Library Science
H Social Sciences Q Science
  • The LC system further breaks these subjects into subclasses by the addition of one or two letters.
  • These letters are followed by numbers up to four digits plus several decimal places in length. For example:
    • For example: Gorillas in the mist LC call number QL737 .P96 F67 1983

QL737 deal with Gorilla Behavior

QL 700 LC call numbers deal with mammals

QL LC call numbers deal with Zoology

Q LC call numbers deal with Science

  • The second part of an LC call number includes a code representing the author and the particular item. This part of the call number begins with a letter followed by numbers, and them sometimes another letter followed by numbers.
    • For example: Gorillas in the Mist call number QL737 .P96 F67 1983
  • Frequently an LC call number will include a final part which represents the year that the item, or particular issue of an item, was published.
    • For example: Gorillas in the Mist call number QL737 .P96 F67 1983

For a detailed list of the major classes and subclasses of the LC classification system, click here.

  1. Locate the item through the library homepage
  2. Write down the complete call number
  3. Note the library and location
  4. Read the call number line by line.
  • ‚ÄčIn the online catalog, the call number is written horizontally in a single line, and is read from left to right. On  a book's label, the parts of the call numbr are stacked vertically, and are read from top to bottom.
    • Find the section where call numbers begin with QL (this is read as a whole number)
    • The numerical numbers are read as a whole numbers.
    • Within this section,scan first alphabetically by letter, then read the numbers as a decimal
    • Sometimes there are numbers after the letter. Read these numbers as decimals.
    • The last line is the year of publication, and is read in chronological order.

For additional help on locating a book in the library, click the Call Number Location link.

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