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Research Guides@Tufts

Library of Congress Call Number Classification: About Library of Congress Call Numbers

Introduction to Library of Congress Call Numbers

The Library of Congress call number scheme is a standard used in academic libraries nationwide. Because books on the same subject are given similar call numbers, LC allows for a high level of consistency between libraries. Thus patrons can be confident that books about Mark Twain will always have PS1331 on their spine.

How to read a Library of Congress Call Number

Most items in Tisch Library are shelved in order of their Library of Congress call number.

First, items are first arranged on the shelves in alphabetical order by letter, as in the example below:

A B  F H J  
JA K KF KFM 
Q  
QA 
T     
Z  

 

Second, within each letter combination, they are arranged by the number:

QA
76
QA
273
QA
273.25
QA
273.4
QA
279
QA
279.2

 

Then, items are arranged by the alpha-numeric segment, which is read as a decimal number. Thus, .M4 is read as M.40 and follows .M388 (read as M.388) on the shelf. Note the final example. The entire last line is treated like a decimal:

 

QA
279         
.H83
QA
279 
.M388      
QA
279       
.M4          
QA
279           
.M44
QA
279
.M5          
QA
279    
.S5          
QA
279        
.T4 W45      

 

See the floor plans of the collections to find the general area of the library where your call number will be located.