What is a call number?
Answer
The numeric or alphanumeric identifier assigned to an item, this unique number is used to shelve and locate items in the Library collection. At Brown we use the Library of Congress call numbers for most of our collections and some local call number schemes. For example, LB1475.5 G72 2006 is located on the fourth floor of the Rockefeller Library.
A good explanation of how to read a Library of Congress call number can be found on the MIT Libraries' website.