Call Number, Class Number, Book Number & Collection Number in Library Classification

Call Number, Class Number, Book Number & Collection Number in Library Classification

Library Academy Team

Define Call Number, Class Number, Book Number & Collection Number in Library Classification Scheme?

What is Call Number

The Call Number is the number that distinctly identifies a book in a library. There are thousands or even more books in a library. The call number is used to identify one particular book in that collection. It also helps in finding the relative location of that book in the whole collection.

Thus, if you know the general sequence of arrangement of books in a library, the call number of a book will guide you to the area and to the exact place where the book is kept.

Call Number = Class Number + Book Number + Collection Number

The Call Number has three parts:

(a) Class Number

(b) Book number

(c) Collection number

What is Class Number

Class number of a book represents its subject. As you know, a classification scheme organizes all the subjects in a systematic order and uses an artificial scheme of numbers, alphabets, and symbols called notation, for each subject.

The notation used for a particular subject in a classification scheme is called it's class number.

Examples: The class number of Library Science is 2 and the class number of Mathematics is B. All the classification schemes use notation to represent different subjects.

Thus, the class number of Library Science in CC is 2 whereas in DDC it is 020. Similarly, the class number of Mathematics in CC and DDC is B and 510 respectively.

what is library call number

Define Book Number

You have understood the class number which is assigned to different books on the basis of their subject. Books of different subjects will have different class numbers.

We need some method to distinguish all the books having the same class number so that these books can be arranged in some order and finds their unique place on the shelf. Books of the same class can be arranged according to book number.

According to Dr. S R Ranganathan “, the book number of a book is a symbol used to fix its position relative to the other books having the same ultimate class”. So, different books on the same subject will have the same class number but different book numbers.

Methods of assigning book numbers

Author’s surname method: It is the most simple method of assigning book numbers. In this method, we use the first three digits of the author’s surname as the book number. In case the author’s surname is not letters given, the book number can be constructed from the forename.


Author’s name               Book number

SR Ranganathan                   RAN

Prof Kasyap                            KAS


DDC: Based on the name of the author under which the first three letters of the name are included.

Example: Ranganathan        RAN

Based on the author's Date of Birth

Example: J64

Based on the year of publication of the book

Example: N33 (1933)

Book Number formula by SR Ranganathan: Colon Book Number System

Dr. SR Ranganathan has given an elaborate scheme of book number consisting of

following fields:

Formula of book number: [L][F][Y][A].[V]-[S];[C]:[Cr] 


L = Language of the book

F = Form in which the book is written e.g. index, list, picture, graph.

Y = Year of publication of the book

A = Accession part of the book number. It is given when more than one books of the same subject published in the same year are acquired in the library

V = Volume the number is given when a multivolume book is acquired in the library

S = Supplement number is given when a supplement is published for a volume

C = Copy number particularly useful for school and college libraries where multiple copies of textbooks are acquired

Cr = Criticism number is used when a book based on some other book is acquired in the library.

Define Collection Number

The collection number, if used, indicates a major grouping within a library or library system.

Libraries generally do not have a single sequence of books. Reference books are separated from other books in most libraries. In school and college libraries textbooks are kept separately.

In university libraries, there may be separate departmental libraries besides separate reference collection. 

Thus, a book maybe in any of the collections in the library and it is necessary to mention the collection where that book is.

The indication of the collection is made by some symbols called collection numbers. Although, a library may devise its own collection number scheme which may help in indicating the collection.

Reading Room      RR

Periodicals Collection    PC

Library Science Department    2D

Physics Department      CD

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  1. +91 63742 90601

  2. Thank you so much. I was trying to understand this topics for an week now. Now, I understood it very well. Now, I can finally write my assignments.

  3. hlo sir blis ki colon ki book ki crection kha se kre plz btana

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