McQuade Library Student Worker Training Guide

Each book is assigned a unique and specific call number- a combination of letters and numbers that designate it by subject and then within subject. No two books or other materials have the same exact call number. Call numbers usually consist of 2 to 4 lines of letters and numbers and are found either on the spine or on the front lower left-hand corner if the spine is too narrow.

• The first line of a call number may begin with one, two, or three letters. These letters should be read alphabetically. A call number that begins with A is shelved before one that begins with B, C, etc.; and a call number that begins with QE is located somewhere before the one that starts with QL. 

• The second line of a call number is made of a number that may have one or more digits. This line is read numerically. A call number with a smaller number in its second line is placed before one that has a larger number for its second line: 

• The third line is the trickiest part of the call number: The letter is shelved alphabetically, and the number following the letter is treated as if it were preceded by a decimal. 

BUT… the tricky part of the 3rd line of the call number is that its numerical component is read as a decimal number. 

• The final lines of the call numbers may include dates, volume indicators, issue numbers, copy numbers, and other annotations such as supplement or index specifiers. These annotations are read after the call number.