When you search for a book in the library's catalog you will see all the copies of the title available throughout the campuses. If its a physical book, you will also see the call numbers of each copy, and its location. Below is an example. If the book is available at the Altoona campus, then you will need that call number to locate the book in our stacks.

Penn State University Libraries uses the Library of Congress Classification System to organize its books and other materials. The call number you find in the catalog is also printed on a spine label on the book itself. In the box above the catalog listed the call number for The World Without Us as GF75.W455 2007. On the spine label, the call number is organized like this.

This arrangement helps to arrange the books on the shelves. Materials are arranged starting at the first line, then if you have items with the same letter or number, they are arranged by what's in the 2nd line and so forth. 

But, how do you read a call number in order to find it on the shelves? 

GF - This first line refers to the general subject of the book. G's are Geography, Anthropology, Recreation. GF's are the subgroup of Human Ecology and Anthropogeography. These subjects are arranged alphabetically on the shelves (So, GFs will come after GEs, but before GNs)

75 - Read this line of numbers as whole numbers. So 75 will come after 9 but before 320.

.W445 - This line is first arranged alphabetically by the letters, then numerically as a decimal. So, .W445 will come before .W5

2007 - This is typically the year the book was published, and are arranged chronologically.