Call Numbers: Finding Items in the Library

Call Numbers: Findings Items in the Library

Each library item (book, DVD, thesis, etc.) has its own unique identifying number, or "call number." This call number is like an address that points you to where the book is located on the shelf. You can find the call number and other location information in the record for the book you want.

What do call numbers mean?

Under the system the UM Libraries use, the call number corresponds to the subject of the item. Each piece of the call number gives more specific information about exactly which book this is. 

How do I read a call number? 

The call numbers the UM Libraries use start with one or two letters, followed by a number, possibly followed by a decimal and another combination of letters and numbers. 

The initial letters are organized alphabetically.

The next number is just a regular number, organized in the usual fashion. 

The letters and numbers after the decimal act just like numbers would after any other decimal. In other words, .55 is between .5 and .6. 

If there is a date on the end of the call number, it's in regular date order. 

Finding a Book on the Shelf

Shelves in the library are labeled with the range of call numbers that are sitting on that shelf. Use what you now know about ordering call numbers to find where the book is located. The shelf in the picture below contains anything between the call numbers TL787.A6 and TN165. 

Help with Call Numbers

If you get stuck reading or finding a call number, ask at the information desk. We're happy to help! If you want more information about the Library of Congress Classification system that the UM Libraries uses, like how the subjects are organized, check out the Library of Congress Classification Outline Links to an external site..