Call numbers correspond to a particular shelf location are intended to help a library user find a book within the library's stacks.
Most academic libraries use the Library of Congress (LC) classification system for their collections. This is because of the higher amount of specificity that the material can attain when using this system. This makes it easier for library users to find the materials that are specific to their topics and research.
Public libraries, on the other hand, tend to use the Dewey Decimal system (DDC), because it classes things more generally, and this makes it easier for library patrons to browse the system.
Here at the Forrer Learning Commons, Library Services actually uses both DDC and LC classification systems. Librarians are currently in the process of switching the materials over from DDC to LC in order to make it easier for a researcher/scholar to conduct their work.
Here's a sample DDC call number:
940.21 G7984s, 2011
What that means:
940: The first number indicates the discipline of the material (900's—History and Geography) and the second and third numbers indicate the subclass of the material (940—the history of Europe).
.21: This further breaks down the classification of the material. Here, the .21 corresponds to European history following 1453.
G7984s,: This letter-number combination refers to the author of the work. Here it uses G to correspond to Greenblatt and uses the numbers following to place Greenblatt within the other authors with last names beginning with G.
2011: Indicates the year of publication.
Here's a sample LC number:
PS 3563 .O8749 B58 1970
What that means:
PS: Indicates the general subject material using a class (P—language and literature) and a subclass (S—American literature).
3563: The number line indicates more specifically the subject of the resource. For example, 3563 indicates an American author writing between 1961 and 2000.
.O8749: This letter-number combination is called a Cutter number and it helps librarians order titles correctly on the shelf, further breaking up the above American author writing between 1961 and 2000.
B58: This letter-number combination corresponds to the first letter of the author's last name or the first letter of the title of the book. In this instance, it is referring to the title of the work, The Bluest Eye.
1970: This number corresponds to the publication year of the material.