Most of our materials are arranged by Library of Congress Call Number, a classification system which groups books together by subject. Grouping similar book together makes it easy to browse for other relevant materials when we find a book of interest on the shelf.

When you find an item in OneSearch, it will indicate a Call Number, a Status, and a Location:  

If the Status is “Available,” the item should be in its proper home in the library. If it is “Currently unavailable,” someone else has checked it out. Once you are signed in to your library account, you can “Request” to recall the book, or look in OneSearch to see if one of our partner libraries has an available copy you can request. You can also use Interlibrary Loan to request a different copy. 

The Location indicates the general area where the item is – Olin Library, Olin Reference, Music Stacks, Science Library, Government Documents, Electronic Book, etc. If it is a digital item, there will be a link to access the content. For physical items in the library, use the call number and the signs posted throughout the stacks to locate the item on the shelf.  

Reading a Library of Congress Call Number

Example: ND1380. R75 2003

ND -  general subject area, on the shelf in alphabetical order

1380 -  further specifies subject area, on the shelf in numerical order within the ND section (read as a whole number - 1380 comes after 1375, before 1385)

.R75 -  often represent the author's last name, on the shelf in alphabetical then decimal order (.R75 comes after .R7 and before .R8)

​2003 - year of publication; presented chronologically on the shelf