Navigating the Library -- Call Numbers

Every item in the UNM University Libraries has a unique call number. The call number appears in the item's record in the LIBROS Online Catalog and on the spine of item itself. Use the call number to find the book on the shelf. Because books are classified by subject, you can often find several helpful books on the same shelf, or nearby. Three classification systems are used:

Library of Congress (LC) classification is used for most materials in LIBROS. LC call numbers start with a letter, A-Z. This system uses a combination of letters and numbers to arrange materials by subjects. In the LIBROS Online Catalog, call numbers are read left to right like this: LB2395 .C65 1991

On the item itself, the call number is read top to bottom like this:

LB - The first line is read in alphabetical order (A, B, BF, C, D ... L, LA, LB, LC, M, ML ... ).
2395 - The second line is read as a whole number (1, 2, 3, ...45, ...100, 101, ... 1000, ... 2000, ...2430, 2431, 2432).
C65 - The third line is a combination of a letter and numbers. Read the letter alphabetically. Read the number as a decimal (C65 = .65).
1991 - This is the year the book was published.

SuDocs is used to file most Government Documents. The Federal Depository Library Program provides an explanation of the Superintendent of Documents Classification System.

Dewey Decimal is commonly found in public library systems. In LIBROS the Deweys start with a number, 000-999.