Answered By: Jenny Horton
Last Updated: Dec 14, 2021     Views: 74

Call numbers organize information into topics.  It's the address where that particular resource lives within the library. The call number is placed on a label that attaches to the item.   

The system divides all knowledge into twenty-one basic classes, each identified by a single letter of the alphabet. Most of these alphabetical classes are further divided into more specific subclasses.

For example, class N, Art, has subclasses

           NA, Architecture;

           NB, Sculpture,

           ND, Painting;

as well as several other subclasses.

Individual topics are often broken down by general to specific topic (Impressionism), specific places (Germany), certain time periods (20th century), etc. Each topic is assigned a single number or a span of numbers.