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The Library Conversion is Complete!


Recently, the library converted from the Dewey Decimal classification system (DDC) to the Library of Congress classification system (LCC). Library staff worked hard to make sure all the books were accurately labeled, shelved, and available for use by you. It might seem like a small change, but there are big benefits in it for students, such as:

  • Making call numbers shorter and more meaningful (meaning it’ll be easier to find that specific book you’re looking for!);
  • Familiarizing you with the system used by libraries at most 4-year institutions (meaning you’ll already know how to use the library at the U if you choose to transfer!);
  • making the collection more inclusive;
  • Creating more space for new subjects;
  • Grouping subjects together so that it's easier to do more accurate research;
  • Giving the librarians the ability to build a better collection for students;

You’ll be able to see this change on the spines of the books: Every book has a label on the spine which shows you its call number. That call number is now in the LCC format. It matches what’s listed on the online catalog. So, if you start your research on the library website, you’ll see the same number listed online and on the spine!

Here’s What it is:

LCC is the most widely-used library classification system in the world. It was developed by the Library of Congress to organize their books. However, because it’s effective, adaptable, and updated regularly, many libraries around the world use it to organize their collections. So, if you walk into a library anywhere in the world, chances are you’ll be able to find a book there using this system! Closer to home, this is the system that most 4-year colleges use, including the U of U. That means, if you are familiar with this system, you can hit the ground running with your research if you transfer to another school.
Because this system is maintained by the Library of Congress, it’s regularly updated to meet new needs. For example, subclassifications can be requested to accommodate works on new technology, such as drones. As drones become more widespread and the number of books about them grows, more subclassifications can be added on military drones, commercial drones, private drones, drone technology, and so on and so forth. It’s an adaptable system that keeps up with the times, making it easier to find resources on very specific topics.

Here's How it Works:

  • The Library of Congress assigns a classification to each book based on subject matter. They have a list of standardized classifications and subclassifications, and more are being added all the time.
  • The call number listed on the spine of the book and in the online catalog will tell you the book’s classification.
  • All LCC call numbers contain both letters and numbers. Every call number will begin with a letter or a combination of letters, which tell you the general classification. Those letters are followed by numbers, which show the subclassification. Check out the cheat sheet below to see what letter corresponds to the areas you’re interested in.
    • PRO TIP: For most students, knowing the general classifications will be enough for you to find not just the resource you’re looking for, but also all the resources on that subject! Check the online catalog to see what letter indicates the classification you’re interested in, then come into the library and browse the shelves!
  • Books are arranged on the shelves alphabetically. So, A comes before AC, which comes before B, etc. The books are then arranged numerically. So, AC 100 comes before AC 200, etc.
  • The system is the same for every book, regardless of the language it’s written in!

Here are the general classifications by subject:

Subject LCC Letter Heading
Agriculture S
Auxiliary Sciences of History (things like archaeology, genealogy, etc.) C
Bibliography, Library Science, Information Resources Z
Education L
Fine Arts N
General Works (things like encyclopedias, dictionaries, etc.) A
Geography, Anthropology, Recreation G
History of the Americas E, F
Language and Literature P
Law K
Medicine R
Military Science U
Music and Books on Music M
Naval Science V
Philosophy, Psychology, Religion B
Political Science J
Science (Math is included here Q
Social Sciences H
Technology T
World History and History of Europe, Asia, Africa, Australia, New Zealand, etc. D


Looking left to right on the library shelves, the classifications will be in this order:
LCC Letter Heading Subject
General Works (things like encyclopedias, dictionaries, etc.) A
Philosophy, Psychology, Religion B
Auxiliary Sciences of History (things like archaeology, genealogy, etc.) C
World History and History of Europe, Asia, Africa, Australia, New Zealand, etc. D
History of the Americas E, F
Geography, Anthropology, Recreation G
Social Sciences H
Political Science J
Law K
Education L
Music and Books on Music M
Fine Arts N
Language and Literature P
Science (Math is included here) Q
Medicine R
Agriculture S
Technology T
Military Science U
Naval Science V
Bibliography, Library Science, Information Resources Z

Now, let's practice!

So, when you look at a record for a book on the online catalog, you will see a call number. Our first example is: PQ8180.17 .A73 C54 2006. Let's break down the call number into its parts.

P Q 8180.17 2006
P tells us this book is in Class P for Language and Literature PQ tells us this book is in the subclassification for French, Italian, Spanish, and Portuguese literature These numbers give us an even more specific subclassification, referring to literature from Spanish America This is the year that this edition was published

Once you’ve seen all this, you’ll know to find PQ alphabetically on the shelves, then the correct title, and even make sure that you have the right edition, all by looking at the spine label!

Let's try another one! The next call number is G142 .S63 2018.

G 142 2018
G tells us that this is in the section for Geography, Anthropology, and Recreation These numbers give us an even more specific subclassification, referring to aerial geography This is the year that this edition was published

One last example. Let's look at the call number Q175.52 .U6 S56 2021.

Q 175 2021
Q tells us that this is in the section for Science These numbers give us an even more specific subclassification, referring to general science This is the year that this edition was published

If you have any questions about locating a book stop by the Reference Desk and one of our librarians will be happy to help you.