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Call Numbers: What they Mean and How to Read Them

This guide will help you understand what call numbers mean and how to use them to find books.

Subject Index

Reading Call Numbers

In the four lines that we see within the call number, the first two are representative of the subject and the second two are organizational for the material itself.

The orange arrow points to the “call letters,” which signifies the section in the Library of Congress Schedule your resource is found. This will also signify the location of the book within the library stacks. Here, the BS stands for Biblical Studies, but be aware that the call letters do not necessarily stand for words starting with those letters.

The red arrow points to the “Call Number”. This is a more specific reference to the subject of the resource. Here, the 1583.53 in addition to the BS is referring to commentaries on the Book of Amos.

Our green arrow gives us the ability to get further understanding of the material we’re looking at. This is the start of our organizing line, and allows us to see the “Cutter” code for the author. This helps in alphabetizing the books within a subject.

Lastly, the blue arrow signifies the year in which the material was published. This can be helpful in determining which edition you’d like of a material.

  • Some call numbers may have additional Cutter numbers (which gives very specific topics from broader top tiers) and volume numbers if the material is in a series.
  • The way that this would be organized would be before 1583.6 but after 1583.5, because the number placement is greater than just .5, but less than .6.

Hiebert Library uses the Library of Congress Classification Schedule to establish call numbers for its books. Each call number has two distinct parts. The first part of the call number organizes the books by subject. The second part organizes the books within their subjects sequentially.

Hiebert Library places each element of the call number on a separate line. When looking for a book, remember to always read call numbers one line at a time. All the books with the same first line will be shelved together, then within that section all books with a matching second line will be together, and so on.

Let’s start by finding a book with the shortest form of a call number, using a hypothetical biblical commentary I wrote on the book of Amos. The call number for that book might be:


In this case the first two lines are the subject lines and the final two lines are the organizing lines. The first line contains the call letter(s). There may be from one to three letters. In this case BS stands for Biblical Studies, but call letters do not necessarily refer to a particular word. The next line is called the call number, and it provides more specific information about the subject of an item. Together BS 1585.53 is the subject area for commentaries on Amos written since 2001

Having found both our call letters and call number, we want to be able to quickly find our book. That’s where the organizing lines come into play. The third line is called a Cutter. Its function is to alphabetize the books within the subject by authors’ last names. My last name is Carter and .C37 is the simple Cutter for my name. If a book does not have an author, then the first word from the title is used for alphabetizing. When comparing two different Cutters, you should read them one character at a time rather than as a whole number.  In this case start with the C, then move to the 3 and finally to the 7. Because they are read this way, the Cutter .C365 would be shelved before the Cutter .C37, and .C4 would come after .C37. Beyond the Cutter there can be additional lines that include a year, volume number, or both. Rarely will you actually need the lines below the Cutter to find the book.

To illustrate the second type of call number the following call number is for a book I hypothetically wrote on humorous things said by Christians. The call number for that book might be:


You may have noticed that this call number has two Cutters instead of one. Some subjects are so big they need to be broken into smaller segments. In this example, BR 115 is Topics in Christianity, and .H84 is Humor. After the topics are sorted, then the organizing can begin in line four as described above.

That’s about all you need to know. If you need any help getting started, please ask any of our friendly library staff. Before you know it, you’ll be helping others learn the ropes.