The call number, the number placed on the spine of the book, is a code that provides valuable information about the book. SLU Libraries use the Library of Congress system to organize materials throughout the general collection.
The following is a brief explanation of how to use these numbers. Please remember, the SLU Libraries Catalog will help you find the call number for each item you want.
Browsing Aid to Library of Congress Classification (PDF)
What are call numbers?
Each book in the library has a unique call number. A call number is like an address in that it tells you where the book is located in the library.
Call numbers appear...
| ...on the spine of the book | ...in the Online Catalog |
| LB 2395 .C65 1991 |
LB2395 .C65 1991 |
Reading call numbers
SLU Libraries, like many academic libraries in the United States, uses the Library of Congress classification system for call numbers. This system uses a combination of letters and numbers to arrange materials by subject.
| LB | Read the first line in alphabetical order |
| 2395 | Read the second line as a whole number |
| .C65 | Read the third line first alphabetically, then as a decimal number |
| 1991 | This is the year that the book was published |
What does the call number mean?
The Library of Congress Classification System arranges materials by subject. The first sections of the call number represent the subject of the book. The letter and decimal section of the call number represent the author's last name. The last section is the year the book was published, but not all books will have this included in the call number.
| LB 2395 |
The first two lines describe the subject of the book: LB2395 = Methods of Study in Higher Education |
| .C65 | The third line typically represents the author's last name: .C65 = Corman |
| 1991 | The last line is usually the year the book was published: 1991 = year of publication |
Putting call numbers in shelf order
This diagram should help you understand how to find your book on the shelf after you have gotten the call number. For locating materials, please consult the Location Guide for Pius Library.
| L before LA | LA before LB | 2395 before 2396 | .C645 before .C65 | 1991 before 1992 | |||||
| L 903 C2 |
LA 11 B53 |
LA 2899 P87 1989 |
LB 2395 C65 1991 |
LB 2395 C65 1991 |
LB 2396 A771 1987 |
LB 2395 C645 1993 |
LB 2395 C65 1991 |
LB 2395 C65 1991 |
LB 2395 C65 1992 |