Reading Library of Congress Call Numbers

Most academic libraries make use of the Library of Congress classification system to organize their collections. The LC system uses a combination of letters and numbers to arrange the books, ensuring that books on the same topic are grouped together. This arrangement results in "serendipitous browsing:" you find one book in the catalog, go to the shelf, and an even better book is sitting right next to it.

From the Online Catalog to the Shelf In the online catalog, the call number will be displayed as a single line of text, divided by decimal points. On the book itself, each decimal point starts a new line of text. In Catalog: LB2396.C65.1991

On Book:

LB 2396

.C65 1991

Finding the Book on the Shelf When locating a book in the stacks, read the call number line by line. For example, if you were trying to find a book with the call number LB2396.C65.1991, you would start by looking on the shelf in alphabetical order for the first line, LB, which would be after L but before LC. Next, read the second line as a whole number: 2395 would come after 2200, but before 2400. After the decimal, you continue to go in alphabetical order, but read all numbers as decimals, not as whole numbers. Following this rule, .C65 would come after .C597 and before .C72. The final line is usually the year the book was published. It is read in chronological order. 1991 comes after 1985 but before 1998. Here is a shelf of books with the call number order explained:

And of course, if you ever have trouble finding a book, you can always ask a librarian!

This handout was made using information from the Online Library Learning Center.