LIBRARY OF CONGRESS (LC) CLASSIFICATION
What is the Purpose of Call Numbers? (though it starts with letters, it is called a number )
Each book has a unique call number (a sequence of letters and numbers together), which provides an "address" or location for the item, and also provides valuable information about it, such as the subject, first letter of the author’s last name, and date of publication. It serves two functions: it groups items on similar topics together, and it helps to distinguish items in the same or similar class. For that reason, no two call numbers are ever the same.
Call numbers appear: on the spine of books and in the Classic Library catalog:
The Library of Congress (LC) Classification System arranges materials by subjects. The first sections of the call number represent the subject of the book.
In the LC Classification System for Literature, here is a sampling of how the call number would begin:
P Language and Literature
PN General Literature (includes drama, theatre, film and television)
PR English Literature
PS American Literature
The letter-and-decimal section of the call number often represents the author’s last name. The last section of a call number is often the date of publication.
|PR||Subject Classification (British literature)||Alphabetical|
|4036||Main Subject (Austen)||Numerical|
|.T6||Author's last name (first initial)||Alphabetical|
|1997||Date of Publication||Numerical|
|Books in the Call Number range A-F1699 reside on the 2nd floor. These are part of the "Circulating" collection, i.e. books that may be checked out of the library. The remaining "circulating" collection (F1700-Z) resides on the 3rd floor.
When you reach the top of the stairs on the 2nd floor, the floor map on the wall is opposite you.
Look to the left and you'll see the stacks at the beginning of the call number range. (See next image below)
The card at the end of each stack row tells you the call number range in that row. For example, B 3776 .W564 N - BD 111 .P tells you that any call number that comes between B 3376 .W564 .N and BD 111 .P (e.g., B 4023 .L) is on the shelf in that stack row.
|When you reach the top of the stairs on the 3rd floor, turn to the right.
Then turn right again until you're standing in the aisle between the stack rows, where the majority of the books on this floor are shelved (see image left).
The call number guide card at the end of each stack row tells you the call number range in that row. For example, PR 3588 .I - PR 4469 tells you that any call number that comes between PR 3588 .I and PR 4469 (e.g., PR 3991 .A1 H68 2012) is on the shelf in that stack row.
NOTE! The books are shelved in a "zig-zag" pattern. As you look at the call number guide card at the end of a stack, note the last call number in that stack. To find books immediately following that call number, first look to the row on the other side of the aisle. In the image above, note the gap between PR 4469 on one guide card and PR 5530 on the other guide card. Look across the aisle to find the stack that has books with call numbers ranging from PR 4470 - PR 5529.
Why is it Important to Know the Structure of a Call Number?
Although the most efficient way to locate materials on a particular topic is usually to perform a subject or keyword search in the Library Catalog and then note the call number for each retrieved item, browsing the shelves can also help you locate material appropriate for your topic.
Since books are classified by subject, you can often find several helpful books on the same shelf, or nearby.
For example, within the subject classifications PR 4036-PR 4038, you will find books about Jane Austen.