How to read a call number
What is a call number?
Think of a call number like an address: it is there to tell you where in the library your book, DVD, or other item is located. Polk Library organizes everything by a system called Library of Congress Classification: all materials are grouped into similar subjects; this means that when you find a book or other resource that you like, there's a good chance several other books which you might also find helpful may be found in the same location!
Call numbers in this system have both letters and numbers, let's take a look at an example:
- In the catalog you've found the book Gladiators: violence and spectacle in ancient Rome, by Roger Dunkle. The call number is: GV35 .D86 2008. Looks complex, let's break it down into four separate lines:
GV Line 1 35 Line 2 .D86 Line 3 2008 Line 4
- Line 1 is read alphabetically. The two letters represent the subject of the resource. A good rule to remember when reading this line is "Nothing before something". On a shelf G would come before GA; GA would come before GB, and so on all the way to GZ. After GZ, the collection would switch to H.
- Line 2 is read in numerical order, as a whole number, from low to high. On a shelf 15 would come before 22; 22 before 35; 35 before 50, and so forth.
- Line 3 is read alphabetically and then numerically as a decimal, again from low to high. On a shelf .C324 would come before .D8599; .D8599 would come BEFORE .D86, and so forth.
- Finally, Line 4 is read numerically from low to high. This line represents the publication year of the book or other resource. In some cases, this number will not appear. On a shelf 1984 comes before 1991; 1991 comes before 2005, and so on until the present year.
- There are guide signs (think of them as neighborhood indicators) with a range posted on the side of each shelf in the library. For instance you might see the range GT42-GZ99, in which case you'd know that the book example listed above would be in that range of shelving. View a photo of this book on the shelf here.