Books and journals are arranged on our shelves according to the Library of Congress (LC) classification system. Each is assigned a unique call number based on its subject matter and other characteristics. Items on the same subject will often be grouped together.
Each call number consists of several elements. For example, consider:
TK
7881.6
M29
1993
The FIRST line, TK, is based on the broad subject of the book. Within Class T for technology, TK represents electrical engineering.
The SECOND line, 7881.6, defines the subject matter more finely. When looking for the book, read this as a whole number with a decimal component. In this example, TK7881.6 represents magnetic recording (a subdivision of TK— electrical engineering).
The THIRD line, M29, usually indicates author, but may also represent a further subject subdivision, geographic area, etc. There may also be a fourth line, formatted the same way. When looking for the book, read the numeric component as if it were preceded by a decimal point. In the example above, the numeric part of M29 should be read as ".29" (and the call number TK7881.6 M29 comes before TK7881.6 M4).
The YEAR of publication, such as 1993, may also be present. These file in chronological order and often indicate successive editions of a book. The call number may also have additional elements, such as volume numbers.
In using a call number to locate a book on the shelf, consider each element in turn before moving on to the next segment.
These call numbers are arranged as they should appear on the shelves. In each case, the element shown in boldface distinguishes the number from the preceding one:
| Q 76 K26 |
QA 17 F75 |
QA 17.1 C98 |
TK 3 Z37 |
TK 29 M49 |
TK 29 M5 1997 |
TK 29 M5 2007 |