A call number is the address of an item on the library shelves. The Eliot D. Pratt Library uses the Library of Congress Classification System (LC) for its collections. LC is subject-based, arranging items by their primary subject.

While there are always some exceptions to the rules, this tutorial will cover what you’re seeing most of the time. Remember, you can always ask the library staff for help understanding or finding items on the shelf.

Here is a brief video on call numbers:

This video was not made by us, so the online catalog and specific locations are different than what you will see, but the basic idea is the same.

Reading Call Numbers – Line by Line

The First Line – General Subject by Letters

LC is broken into 21 general subjects represented by letters. This allows libraries to classify and arrange larger collections by the main subject matter of the text.

LC then breaks into more specific subjects by the addition of 1-2 letters. For the most common LC subject breakdowns, see the list at the bottom of this page or the posters at the end of the stacks in the library.

These are read in alphabetical order, where L comes before LA, which comes before LC, which all comes before M.

The Second Line – Specific Subject by Numbers

LC is hierarchical, using numbers up to four digits in length (1-9999), sometimes with several decimal places, to drill down to the most specific subject. For example:

• LC call numbers beginning with L deal with Education
• LC call numbers beginning with LB deal with Theory & Practice of Education
• LC call numbers in the LB 51-885 range deal with Systems of Individual Educators & Writers
• LC call numbers in the LB 880-885 range deal with the period 1951-present
• LC call numbers in LB 880 deal with Educators Outside the US
• The LC call number for Pedagogy of the Oppressed by Paolo Freire is: LB880.F73 P4313 2002

These are read in simple numerical order, where 7 comes before 70, which comes before 700, which comes before 7000.

The Third Line – Author coded by Letters & Numbers

LC always includes a code representing the author. This part of the call number begins with a decimal and the first letter of the author’s surname followed by numbers representing some of the subsequent letters, for example:

• Pedagogy of the Oppressed by Paolo Freire is: LB880.F73 P4313 2002

These are read first in alphabetical and then in decimal order, where .O9615 comes before .P9615 and where .P9615comes before .P962

The Fourth Line – Title coded by Letters & Numbers

LC sometimes includes a code representing the title, especially in areas where there may be many titles by the same author. This part of the call number begins with the first letter of the title – excluding A, An, The, etc. – followed by numbers representing some of the subsequent letters, for example:

• Pedagogy of the Oppressed by Paolo Freire is: LB880.F73 P4313 2002

These are read first in alphabetical and then in decimal order (even though the decimal is usually not present), where O9615 comes before P9615 and where P9615 comes before P962

The Fifth Line – Year of Publication

LC usually includes a year of publication. This is almost always present on newer titles, but sometimes absent on older materials

• Pedagogy of the Oppressed by Paolo Freire is: LB880.F73 P4313 2002

These are read by oldest to newest, where LB880.F73 P4313 comes before LB880.F73 P4313 1993, which comes before LB880.F73 P4313 2002

Other Lines – Locations, copies, volumes, etc.

Information that precedes the LC Call Number is included by the library to help you find what you’re looking for when items are not shelved in the main collection with the bulk of our print books. For instance, we’ll add something like DVD before the call number if it’s a video or REF if it’s a Reference item.

Information that follows the LC Call Number can vary. It may be volume, issue, or copy number to let you find the exact item you’re looking for without having to pull it off the shelf. It may also be location information, like Special Collection, to let you know it’s not shelved with the main collection.

Reading Call Numbers – All Together Now!

Call numbers are read from left to right and from top to bottom. In the catalog, a call number is written out all on one line but on the item it is displayed in a column, as below. This is so it will fit on the item’s spine whenever possible and be visible when shelved. This is called a spine label. Call numbers are read the same way whether they’re all on one line or in a column. For example:

One line, as in the catalog: LB880.F73 P4313 2002

In a column, as on a spine label:

Always remember to note the location and availability of an item before you go looking for it. If an item is checked out, missing, or on display, the catalog will tell you so under the item record.

Library of Congress Classification System

This is a basic outline of the LC General Subjects. For a more specific list, check out the Library of Congress Classification Outline. This may be helpful in cases where further breakdown of subjects, for instance by time period, is not obvious and you want to be able to browse more efficiently.

Primary Class:
A | B | C | D | E-F | G | H | J | K | L | M |
N | P | Q | R | S | T | U | V | Z |