Note the absence of I and O, letters that can be easily confused with numbers.
The system is used by most college and university libraries to organize books on the library shelves. It is an alpha-numeric system. Each item in the library has a label with letters and numbers (together called a ) which indicates its place on the shelf. The letters indicate a subject area, and the numbers which follow further subdivide the broader topic into more specific categories.
Start with a search in the library catalog or use the search box below. After locating the page for a specific title, scroll down to "Find a copy in the library" and the call number will be listed for the book.
Library of Congress