Library of Congress (LOC) Classification is a system developed by the Library of Congress in Washington D.C. as a way of organizing very large numbers of books into subject areas by a series of letters and numbers. PHSC, and most academic libraries, use this system. Every item cataloged is given a special series of letters followed by numbers that place the item on the shelf with others in the same subject area. LOC call numbers are arranged from A through Z, and each letter stands for a broad subject.
Check out the Library of Congress Classification Outline here: https://www.loc.gov/catdir/cpso/lcco/
The Library of Congress is the largest library in the world, containing millions of books, manuscripts, and other important material.
Check out the Library of Congress Catalog here: https://www.loc.gov/
A tip from your librarians: At public or school libraries, a different system is used. This system is called the Dewey Decimal system and the call number usually begins with a number using a decimal and ends with the abbreviation of the author's last name.
