When you think of libraries, you usually think of books. Lots of books. And you wonder how there could be so many housed in one building. And how you can find where one particular book is located. And now there is so much more than books. There are fiction and nonfiction books. Hardcover and paperback books. Small “trade paperback” books. Large print books. Children’s and teenagers’ books. And books on CD. And DVDs. And blu-ray movies. And music CDs. It’s enough to be intimidating to the causal library user.

Well, fear no more. In the next few installments of “Understanding CPL Call Numbers,” I am going to give you a brief thumbnail sketch of the call number system used by CPL (Chesapeake Public Library), which will hopefully take the mystery out of navigating call numbers. In this first installment, though, I am going to spend a little time defining a few terms that will enable the rest of the installments to make more sense. In the installments to follow, I will give you more detail about the letters and numbers as they relate to fiction and nonfiction, children and young adult materials, and audio-visual materials.  With this guide in hand, then, you will be armed with all you need to be able to find any item on any shelf in any Chesapeake Public Library!

When you look up a book (or any kind of item) in the CPL catalog, have identified the item you want and know it is available in the library building you are standing in, you are off to an excellent start! But before you proceed to the shelves to find the item, you’ll want to know just what to look for so that you will know when you have found the correct item. Before I start with that explanation, though, I need to define a few terms: “call number,” “Dewey Decimal number” and “spine label.” Then I will give a short overview of the most common call numbers found on fiction books for adults.

Dewey Decimal number for a nonfiction book.
Call Number for a fiction novel.

Not to be confused with a radio station’s call letters, the call number refers to the classification code by which the book or item is stored in the library. Call numbers, at least at CPL, do not always have to be literally numbers; they are often just a combination of letters and a name (but again, try not to think of “call letters”). As a rule, call numbers with just letters and words or names are fiction, and Dewey Decimal numbered items are non-fiction. Call numbers will usually look like this: “F KARON” or “320.973 CLI 2011.”

[illustration courtesy of www.wikipedia.org]

Practically everyone has heard of “Dewey Decimal” numbers one or two times in their lives, but many might not know how the system actually works. Melvil Dewey (1851-1931) is the inventor of the system most public libraries use to classify items on their shelves, and CPL is no exception. In short, Dewey Decimal numbers always begin with a 3-digit number, followed by a period, then more numbers (from one to as many as five or six numbers), then (at least in CPL) the first three letters (capital letters) of the last name of the author, followed by the year the item was published, especially in the case of books published within the last ten years.

In the Dewey Decimal system there is a number for each subject. The three-digit number at the beginning of a Dewey Decimal call number is the most general subject number, while the numbers after the decimal point refer to narrower, specific aspects of the subject that pinpoint the subject matter precisely. In general, the way this process works is that The Library of Congress assigns these basic numbers to each item that gets published, and public libraries, when they catalog these items for their particular system, adopt the same basic numerical sequence but may add or subtract a few letters or numbers toward the end of the number as best fits their system. Later, in the installment covering non-fiction, I will go into a little bit more detail regarding subjects and the Dewey Decimal numbers representing each general subject.

Spine label with Dewey Decimal number.

The Dewey Decimal number for each and every item housed in CPL is displayed on the “spine label” of the item. The spine label is always a small white sticky-label that is found on the spine of a book, near the bottom of the spine of the book. The spine label displays in clear, easy-to-read text the call number of the item, whether non-fiction or fiction. Many fiction items can be found with a “genre label” on the spine of the book directly above the numerical spine label. Examples of genre labels include “romance,” “urban fiction,” “mystery” and so on, to indicate which category of fiction the item belongs to.

In later installments, I will have a lot more to say about non-fiction. But for the moment, let’s just focus on the fiction. CPL fiction call numbers are pretty simple to understand, especially once you know what the first letter in fiction call numbers stands for. Five of the most common “one-letters” you will see are F, O, M, PBK and GRAPHIC NOVEL.

“F” stands for, of course, fiction (for adults). Thus “F KARON” is the call number of a fiction book for adults by Jan Karon. The call number “F” signifies hard-cover fiction as well as large-paperback fiction.

Text in a large print novel.

“O” stands for large print. A large print book has text graphics that are a much larger size than normal sized print. For some readers, large print books are easier on the eyes when reading. “O” replaces the “F” in the call numbers of large print fiction books. Thus, “O KARON” instead of “F KARON” is the call number for large print fiction books by author Jan Karon.

The M on the spine label stands for Mystery.


“M” stands for “mystery.” Many authors who write mysteries have those of their books that are designated mysteries cataloged with an “M” instead of the usual “F.” An example is James Patterson (and Maxine Patetro), The 9th Judgment, which bears the call number “M PATTERSON J.”

Paperbacks are indicated by the PBK in the call number.

“PBK” stands for those small, trade-paperback sized books that you will often find sold in Wal-Mart, drug stores, airport terminals and the like. Thus “PBK MACOMBER” signifies a trade paperback book by Debbie Macomber.


“GRAPHIC NOVEL F,” signifies adult graphic novels, which are actual stories, often of novel length, that are written in cartoon format, rather than the straightforward narrative text usually found in novels. Just because graphic novels are written with cartoon figures, does not necessarily mean that they are any less serious in tone and intent. Graphic novels meant for adults should not be confused with comic books, like a Garfield book or a Beetle Bailey book and so on. Manga is a very popular type of graphic novel from Japan, though well-known authors such as Stephen King have graphic novel adaptations of their books. Often the difference between adult, young adult and children’s graphic novels is simply the age-level appropriateness of their content.

Next installment: a closer look at fiction and paperbacks.

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One thought on “Understanding CPL Call Numbers Part 1

  1. I loved this! Particularly the bit where you explain the difference between Manga and Graphic novels which are different but some people don’t know that! I think a lot of people assume that graphic novels are for kids because they look like comics but they can be just as complex as novels.

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