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C-1 
Appendix C 
Code 39 Specifications 
Code 39 (or Code 3 of 9) is the de facto standard of non-retail American 
industry. It is widely used in the automotive industry (AIAG specifications) 
as well as in government and military applications (LOGMARS specifi-
cations). Code 39 is flexible, features a large character set, variable data 
length and density, and bi-directional readability. Code 39 is extremely 
accurate; substitution errors are almost nonexistent.  Its character set 
consists of numbers 
through 9, upper case A-Z, and characters Space, $
%/ + and  -
The name "Code 39" comes from both the fact that its 
character set originally contained 39 characters (it 
now has 43) and from its structure. Each character is 
formed of three wide and six narrow elements, made 
up of five bars and four spaces.  Code 39's density can 
vary from a low of .75 characters per inch (cpi) to a 
high of 9.4 cpi.  There should be a ¼" "quiet zone
(white space) to the left and right of the bar code.  
Code 39 uses an asterisk (
*) as a start and stop character. This character 
must precede and follow the data in the bar code.  The RF Terminal gives 
you the option of transmitting or not transmitting these characters when the 
bar code is read.  
Exact specifications for Code 39 and other bar code symbologies can be 
obtained from ANSI at the address below: 
American National Standards Institute 
Customer Service 
11 West 42
nd
 St. 
New York,  NY   10036 
http://web.ansi.org 
document ANSI/AIM BC1-1995 
Code 39 has several advanced features and functions that are discussed 
further in this appendix.  
*C39*