What do these call numbers mean?

We use the Library of Congress Classification (LCC) system for items in the library. LCC is an alpha-numeric system used by academic libraries to organize books by discipline. It divides all knowledge into 21 main classes, identified by a single letter (e.g., Q for Science). These are further broken down into subclasses using more letters (e.g., QE for Geology) and numbers that get progressively more specific, with a final letter/number combination often representing the author's last name to provide a precise address for the book on the shelf.

How it works

Subject categories: The system is divided into 21 main classes, each with a single letter (e.g., A for General Works, B for Philosophy/Religion, Q for Science, R for Medicine).
Subclasses: Each main class is further divided into subclasses, often using two or three letters, which narrow the topic (e.g., BF for Psychology within the B class).
Hierarchy: Within each subclass, numerical ranges are used to classify topics from general to specific.
Call number: The combination of these letters and numbers is the book's "call number," which is its specific address on the shelf.
- Example call number: BF 204.5 .S75 2010
  - BF: Psychology (subclass of B)
  - 204.5: A specific topic within psychology
  - .S75: The author's last name (implied decimal before the S)
  - 2010: The year of publication