Skip to Main Content


Q. What is a classmark?

Answered By: Sharon Nangle
Last Updated: Dec 23, 2019     Views: 11

The University of St Andrews Library uses the Library of Congress Classification system.  This answer explains how the classification system works - giving a brief explanation using an example, and then a more detailed explanation for those who want to know more.

Library classification seeks to ascertain the intellectual “aboutness” of a work and assign a suitable, identifying classmark. This will allow the work to be physically located beside other, similar works.

The classmark for the 10th edition of Economics” by Begg, Fischer and Dornbusch, is HB171.B44G11

Which can be broken down like this:

  • “H” is for the broad subject of “Social Sciences”
    • “HB” is the subclass for “Economic Theory”
      • “HB171” is for general works on economic theory in English and published after 1876
        • “B44” represents the “B”, “E” and “G” of “Begg”
          • “G11” represents the publication date of “2011

More about the Library of Congress Classification System:

The Library of Congress classification system divides all knowledge into twenty-one basic classes, each identified by a single letter of the alphabet.

Each of the main classes (with the exception of E and F) is further divided into subclasses, which represent disciplines or major branches of the main class.

Most subclasses are denoted by two letter, or occasionally three-letter combinations.

For example, among the subclasses for class N, Art are:

  • NA, Architecture
  • NB, Sculpture
  • ND, Painting

Each subclass is further subdivided, representing components of the subclass to specify form, place, time & subtopics. These are denoted by integers 1-9999, some with decimal extension.

So, how does it work?

Let’s take the popular textbook by Begg, Fischer and Dornbusch. Entitled simply “Economics”, the most recent edition currently available in the library is the 10th. This edition was published in 2011. The classmark for this edition is given as:


Firstly, we establish the “aboutness” of the work. This will be represented by the letters and numbers to the left of the decimal point. In this case, it’s clearly about economics. Economics comes under “Social Sciences” in the Library of Congress system, so we have “H” as our starting point.

Within “H”, the subclass “HB” is for “Economic Theory”.

From there we can narrow further still to “HB171”, which is for general works on economic theory, from 1876 onwards and published in English.

Over on the right hand side of the decimal point, we can then differentiate this from similar works by different authors. So, we use an alphanumeric “Cutter” (named after Charles Amni Cutter, who devised this method) number to represent the author’s surname. In this case we use B44 to represent the “B”, “E” and “G” of “Begg”.

Finally, we’d want to differentiate the numerous of editions of the work. To achieve this, we add a date cutter. Again, this is an alphanumeric representation of century and year.

Here, “G” represents a date of publication in the 21st century and “11” is the 11th year of that century.

Therefore, “G11” represents “2011”. In similar fashion, “F97” would represent “1997”. The 5th edition of the work was published in 1997, so the complete classmark is: HB171.B44F97

So, all editions should sit together on the shelves in order of publication date.

It should be noted that date cutters are used as required and will not be present on all classmarks.

Related Topics

Chat with us