ISO/IEC 16388:2023

Information technology — Automatic identification and data capture techniques — Code 39 bar code symbology specification

This document specifies the requirements for the bar code symbology known as Code 39. This document specifies Code 39 symbology characteristics, data character encodation, dimensions, tolerances, decoding algorithms and parameters to be defined by applications. This document specifies the symbology identifier prefix strings for Code 39 symbols.

Technologies de l'information — Techniques automatiques d'identification et de capture des données — Spécifications des symbologies des codes à barres, code 39

General Information

• Status: Published
• Publication Date: 10-May-2023
• ICS: 01.080.50 - Graphical symbols for use on information technology and telecommunications technical drawings and in relevant technical product documentation
• ICS: 35.040.50 - Automatic identification and data capture techniques
• Technical Committee: ISO/IEC JTC 1/SC 31 - Automatic identification and data capture techniques
• Drafting Committee: ISO/IEC JTC 1/SC 31/WG 1 - Data carrier
• Current Stage: 6060 - International Standard published
• Start Date: 11-May-2023
• Due Date: 08-Mar-2024
• Completion Date: 11-May-2023

Relations

• Revises: ISO/IEC 16388:2007 - Information technology — Automatic identification and data capture techniques — Code 39 bar code symbology specification
• Effective Date: 23-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 16388
Third edition
2023-05
Information technology — Automatic
identification and data capture
techniques — Code 39 bar code
symbology specification
Technologies de l'information — Techniques automatiques
d'identification et de capture des données — Spécifications des
symbologies des codes à barres, code 39
Reference number
ISO/IEC 16388:2023(E)
© ISO/IEC 2023

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ISO/IEC 16388:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
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ISO/IEC 16388:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definition . 1
4 Requirements. 1
4.1 Symbology characteristics. 1
4.2 Symbol structure . 2
4.3 Character encodation . 3
4.3.1 Symbol character structure . 3
4.3.2 Symbol character assignments. 3
4.3.3 Start and stop characters . 4
4.3.4 Optional symbol check character . 4
4.4 Dimensions . 4
4.5 Reference decode algorithm . 5
4.6 Symbol quality . 6
4.6.1 Test specification . 6
4.6.2 Additional parameters . 6
4.7 Application-defined parameters . 7
4.7.1 Symbology and dimensional characteristics . 7
4.7.2 Optical specifications . 7
4.7.3 Test specifications . 8
Annex A (informative) Additional features . 9
Annex B (informative) Guidelines for the use of Code 39 .12
Annex C (normative) Symbology identifier .14
Annex D (informative) Example of application-defined parameters .15
Bibliography .17
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ISO/IEC 16388:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance
are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria
needed for the different types of ISO documents should be noted. This document was drafted in
accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
www.iec.ch/members_experts/refdocs).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/
or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC list of patent
declarations received (see patents.iec.ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 31, Automatic identification and data capture techniques.
This third edition cancels and replaces the second edition (ISO 16388:2007), which has been technically
revised.
The main changes are as follows:
— the grading of parameter “Inter character gap” in 4.6.2.2 has been corrected;
— a NOTE has been added below Table A.2 about possible alternate representation of a minus sign, a
period or the numbers 0 to 9 by character pairs.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.
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ISO/IEC 16388:2023(E)
Introduction
The technology of bar coding is based on the recognition of patterns encoded in bars and spaces of
defined dimensions. There are numerous methods of encoding information in bar code form, known as
symbologies. Code 39 is one such symbology. The rules defining the translation of characters into bar
and space patterns and other essential features are known as the symbology specification.
In the past, symbology specifications were developed and published by a number of organizations,
resulting in certain instances in conflicting requirements for certain symbologies.
Manufacturers of bar code equipment and users of bar code technology require publicly available
standard symbology specifications to which they can refer when developing equipment and application
standards.
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INTERNATIONAL STANDARD ISO/IEC 16388:2023(E)
Information technology — Automatic identification and
data capture techniques — Code 39 bar code symbology
specification
1 Scope
This document specifies the requirements for the bar code symbology known as Code 39. This
document specifies Code 39 symbology characteristics, data character encodation, dimensions,
tolerances, decoding algorithms and parameters to be defined by applications. This document specifies
the symbology identifier prefix strings for Code 39 symbols.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 646, Information technology — ISO 7-bit coded character set for information interchange
ISO/IEC 15416, Automatic identification and data capture techniques — Bar code print quality test
specification — Linear symbols
ISO/IEC 15424, Information technology — Automatic identification and data capture techniques — Data
Carrier Identifiers (including Symbology Identifiers)
ISO/IEC 19762, Information technology — Automatic identification and data capture (AIDC) techniques —
Harmonized vocabulary
3 Terms and definition
For the purposes of this document, the terms and definitions given in ISO/IEC 19762 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Requirements
4.1 Symbology characteristics
The characteristics of Code 39 are as follows.
a) Encodable character set:
1) full alphanumeric A to Z and 0 to 9 (ASCII characters 65 to 90 and 48 to 57 inclusive, in
accordance with ISO/IEC 646 IRV);
2) special characters: space $ % + - . / (ASCII characters 32, 36, 37, 43, 45, 46 and 47, respectively,
in accordance with ISO/IEC 646 IRV);
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ISO/IEC 16388:2023(E)
3) start/stop character.
b) Code type: discrete.
c) Elements per symbol character: 9, of which 3 wide and 6 narrow, comprising 5 bars and 4 spaces.
d) Character self-checking: yes.
e) Data string length encodable: variable.
f) Bidirectionally decodable: yes.
g) Symbol check character: one, optional (see Annex A).
h) Symbol character density: 13 to 16 modules per symbol character, inclusive of minimum
intercharacter gap, depending on wide/narrow ratio.
i) Non-data overhead: equivalent to 2 symbol characters.
j) Symbology identifier shall comply as described in Annex C.
NOTE Usage guidelines are given in Annex B.
4.2 Symbol structure
As illustrated in Figure 1, Code 39 symbols shall comprise:
a) leading quiet zone;
b) start character;
c) one or more symbol characters representing data (including symbol check character, if present);
d) stop character;
e) trailing quiet zone.
A space, the intercharacter gap, shall separate characters within the symbol.
Key
1 quiet zone
2 start character
3 character "1"
4 character "A"
5 stop character
Figure 1 — Code 39 symbol
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ISO/IEC 16388:2023(E)
4.3 Character encodation
4.3.1 Symbol character structure
Each symbol character comprises nine elements (five bars and four spaces) of which six are always
narrow (either three narrow bars and three narrow spaces, or five narrow bars and one narrow space)
and three are always wide (one wide space and two wide bars when there are three narrow bars, or
three wide spaces when there are five narrow bars). This parity feature enables character self-checking
to be carried out.
4.3.2 Symbol character assignments
Table 1 defines all the Code 39 character assignments.
Table 1 — Code 39 character assignments
ASCII
Char. Encodation pattern B S B S B S B S B
Value
(decimal)
0       0 0 0 1 1 0 1 0 0 48
1       1 0 0 1 0 0 0 0 1 49
2       0 0 1 1 0 0 0 0 1 50
3       1 0 1 1 0 0 0 0 0 51
4       0 0 0 1 1 0 0 0 1 52
5       1 0 0 1 1 0 0 0 0 53
6       0 0 1 1 1 0 0 0 0 54
7       0 0 0 1 0 0 1 0 1 55
8       1 0 0 1 0 0 1 0 0 56
9       0 0 1 1 0 0 1 0 0 57
A       1 0 0 0 0 1 0 0 1 65
B       0 0 1 0 0 1 0 0 1 66
C       1 0 1 0 0 1 0 0 0 67
D       0 0 0 0 1 1 0 0 1 68
E       1 0 0 0 1 1 0 0 0 69
F       0 0 1 0 1 1 0 0 0 70
G       0 0 0 0 0 1 1 0 1 71
H       1 0 0 0 0 1 1 0 0 72
I       0 0 1 0 0 1 1 0 0 73
J       0 0 0 0 1 1 1 0 0 74
K       1 0 0 0 0 0 0 1 1 75
L       0 0 1 0 0 0 0 1 1 76
M       1 0 1 0 0 0 0 1 0 77
N       0 0 0 0 1 0 0 1 1 78
O       1 0 0 0 1 0 0 1 0 79
P       0 0 1 0 1 0 0 1 0 80
Q       0 0 0 0 0 0 1 1 1 81
R       1 0 0 0 0 0 1 1 0 82
NOTE 1  S/S denotes the start and stop character, usually graphically represented as *.
NOTE 2  In the columns headed B and S, 0 represents a narrow element and 1 a wide element.
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ISO/IEC 16388:2023(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
ASCII
Char. Encodation pattern B S B S B S B S B
Value
(decimal)
S       0 0 1 0 0 0 1 1 0 83
T       0 0 0 0 1 0 1 1 0 84
U       1 1 0 0 0 0 0 0 1 85
V       0 1 1 0 0 0 0 0 1 86
W       1 1 1 0 0 0 0 0 0 87
X       0 1 0 0 1 0 0 0 1 88
Y       1 1 0 0 1 0 0 0 0 89
Z       0 1 1 0 1 0 0 0 0 90
hyphen       0 1 0 0 0 0 1 0 1 45
period       1 1 0 0 0 0 1 0 0 46
space       0 1 1 0 0 0 1 0 0 32
$       0 1 0 1 0 1 0 0 0 36
/       0 1 0 1 0 0 0 1 0 47
+       0 1 0 0 0 1 0 1 0 43
%       0 0 0 1 0 1 0 1 0 37
S/S or *       0 1 0 0 1 0 1 0 0 none
NOTE 1  S/S denotes the start and stop character, usually graphically represented as *.
NOTE 2  In the columns headed B and S, 0 represents a narrow element and 1 a wide element.
4.3.3 Start and stop characters
The Code 39 start and stop character is usually depicted in human-readable form by an * (asterisk). This
character shall not form part of the data encoded elsewhere in the symbol and shall not be transmitted
by the decoder.
The start character shall be positioned at the normal left end of the data symbol characters, separated
from the first bar of the leading data character by an intercharacter gap. The stop character shall be
positioned at the normal right end of the data symbol characters (including symbol check character if
present), separated from the final bar of the trailing data character by an intercharacter gap.
4.3.4 Optional symbol check character
Annex A defines the symbol check character position and calculation.
4.4 Dimensions
Code 39 symbology shall use the following nominal dimensions.
a) Width of narrow element (X): the X dimension of Code 39 symbols should be defined by the
application specification having due regard to the availability of equipment for the production and
reading of symbols and complying with the general requirements of the application. See 4.7.1.
b) Wide/narrow ratio (N): 2,0 : 1 to 3,0 : 1.
c) Width of intercharacter gap (I):
1) minimum: equal to X;
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ISO/IEC 16388:2023(E)
2) maximum:
for X < 0,287 mm: 5,3X;
for X ≥ 0,287 mm: 1,52 mm or 3X, whichever is greater.
d) Minimum width of quiet zone: 10X.
e) Recommended minimum bar code height for manual scanning: 5,0 mm or 15 % of symbol width
excluding quiet zones, whichever is greater.
NOTE The width, W (in millimetres), of a Code 39 symbol, including quiet zones, can be calculated from the
following expression:
WC=+()23()NX+61++()CI+2Q
where
W is the symbol width;
C is the number of data characters (including symbol check character if used);
N is the wide/narrow ratio;
X is the width of a narrow element in millimetres;
l is the width of the intercharacter gap in millimetres;
Q is the width of the quiet zone in millimetres.
4.5 Reference decode algorithm
Bar code reading systems are designed to read imperfect symbols to the extent that practical
algorithms permit. This subclause describes the reference decode algorithm used in the computation of
the decodability value described in ISO/IEC 15416.
a) Confirm presence of a leading quiet zone.
b) For each symbol character (including start and stop characters):
1) Measure the total width of 5 bars and 4 spaces; which is S.
2) Compute a threshold value, T = S / 8.
3) Compare each element width for that character with the value T. If element width is greater
than T, assume element is wide; if not, assume element is narrow.
4) Determine if pattern of wide and narrow elements matches a valid character from the allowable
set.
c) The first symbol character read has to be a start/stop character, from which the scan direction can
be deduced.
d) Continue character reading until a valid start/stop character is encountered.
e) Confirm presence of a trailing quiet zone.
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ISO/IEC 16388:2023(E)
4.6 Symbol quality
4.6.1 Test specification
In order to verify whether a symbol meets the specifications in this document, it shall be tested using the
test specification defined in ISO/IEC 15416, which defines a standardized methodology for measuring
and grading bar code symbols, as supplemented in 4.6.2. ISO/IEC 15416 lays down conditions under
which measurements should be made, and defines methods of determining an overall quality grade
based on the attributes of the bar code symbol. The reference decode algorithm defined in 4.5 shall be
used for the assessment of the "decode" and "decodability" parameters under ISO/IEC 15416.
The overall sy
...

DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 16388
ISO/IEC JTC 1/SC 31 Secretariat: ANSI
Voting begins on: Voting terminates on:
2022-03-28 2022-06-20
Information technology — Automatic identification and
data capture techniques — Code 39 bar code symbology
specification
Technologies de l'information — Techniques automatiques d'identification et de capture des données —
Spécifications des symbologies des codes à barres, code 39
ICS: 01.080.50; 35.040.50
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
This document is circulated as received from the committee secretariat.
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/IEC DIS 16388:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO/IEC 2022

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ISO/IEC DIS 16388:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
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ISO/IEC DIS 16388:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 1
4.1 Symbology characteristics. 1
4.2 Symbol structure . 2
4.3 Character encodation . 2
4.3.1 Symbol character structure . 2
4.3.2 Symbol character assignments. 3
4.3.3 Start and stop characters . 4
4.3.4 Optional symbol check character . 4
4.4 Dimensions . 4
4.5 Reference decode algorithm . 5
4.6 Symbol quality . 5
4.6.1 Test specification . 5
4.6.2 Additional parameters . 6
4.7 Application‑defined parameters . 7
4.7.1 Symbology and dimensional characteristics . 7
4.7.2 Optical specifications . 7
4.7.3 Test specifications . 7
Annex A (informative) Additional features . 8
Annex B (informative) Guidelines for the use of Code 39 .11
Annex C (normative) Symbology identifier .13
Annex D (informative) Example of application-defined parameters .14
Bibliography .16
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ISO/IEC DIS 16388:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non‑governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/IEC JWG1, Information technology,
Subcommittee SC 31, Automatic identification and data capture techniques.
This third edition cancels and replaces the second edition (ISO 16388:2007), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— Corrected grading of parameter “Inter character gap” in section 4.6.2.2
— Note added below Table A.2 about possible alternate representation of a minus sign, a period or the
numbers 0 to 9 by character pairs.
A list of all parts in the ISO ##### series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
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ISO/IEC DIS 16388:2022(E)
Introduction
The technology of bar coding is based on the recognition of patterns encoded in bars and spaces of
defined dimensions. There are numerous methods of encoding information in bar code form, known as
symbologies. Code 39 is one such symbology. The rules defining the translation of characters into bar
and space patterns and other essential features are known as the symbology specification.
In the past, symbology specifications were developed and published by a number of organizations,
resulting in certain instances in conflicting requirements for certain symbologies.
Manufacturers of bar code equipment and users of bar code technology require publicly available
standard symbology specifications to which they can refer when developing equipment and application
standards.
Identification of patent holders: the following text shall be included if patent rights have been identified.
The International Organization for Standardization (ISO) [and/or] International Electrotechnical
Commission (IEC) draw[s] attention to the fact that it is claimed that compliance with this document
may involve the use of a patent.
ISO [and/or] IEC take[s] no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured ISO [and/or] IEC that he/she is willing to negotiate licences
under reasonable and non‑discriminatory terms and conditions with applicants throughout the world.
In this respect, the statement of the holder of this patent right is registered with ISO [and/or] IEC.
Information may be obtained from the patent database available at www.iso.org/patents.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights other than those in the patent database. ISO [and/or] IEC shall not be held responsible for
identifying any or all such patent rights.
v
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DRAFT INTERNATIONAL STANDARD ISO/IEC DIS 16388:2022(E)
Information technology — Automatic identification and
data capture techniques — Code 39 bar code symbology
specification
1 Scope
This International Standard specifies the requirements for the bar code symbology known as Code 39;
it specifies Code 39 symbology characteristics, data character encodation, dimensions, tolerances,
decoding algorithms and parameters to be defined by applications. It specifies the Symbology Identifier
prefix strings for Code 39 symbols.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 646, Information technology — ISO 7-bit coded character set for information interchange
ISO/IEC 15416, Automatic identification and data capture techniques — Bar code print quality test
specification — Linear symbols
ISO/IEC 15424, Information technology — Automatic identification and data capture techniques — Data
Carrier Identifiers (including Symbology Identifiers)
ISO/IEC 19762, Information technology — Automatic identification and data capture (AIDC) techniques —
Harmonized vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 19762 apply.
4 Requirements
4.1 Symbology characteristics
The characteristics of Code 39 are as follows.
a) Encodable character set:
1) full alphanumeric A to Z and 0 to 9 (ASCII characters 65 to 90 and 48 to 57 inclusive, in
accordance with ISO 646).
2) special characters: space $ % + ‑ . / (ASCII characters 32, 36, 37, 43, 45, 46 and 47, respectively,
in accordance with ISO 646).
3) start/stop character.
b) Code type: discrete.
c) Elements per symbol character: 9, of which 3 wide and 6 narrow, comprising 5 bars and 4 spaces.
d) Character self‑checking: yes.
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ISO/IEC DIS 16388:2022(E)
e) Data string length encodable: variable.
f) Bidirectionally decodable: yes.
g) Symbol check character: one, optional (see Annex A).
h) Symbol character density: 13 to 16 modules per symbol character, inclusive of minimum
intercharacter gap, depending on wide/narrow ratio.
i) Non‑data overhead: equivalent to 2 symbol characters.
j) Symbology identifier as described in Annex C.
NOTE Usage guidelines are given in Annex B.
4.2 Symbol structure
As illustrated in Figure 1, Code 39 symbols shall comprise
a) leading quiet zone;
b) start character;
c) one or more symbol characters representing data (including symbol check character, if present);
d) stop character;
e) trailing quiet zone.
A space, the intercharacter gap, shall separate characters within the symbol.
Key
a Quiet zone
b Start character
c Character "1"
d Character "A"
e Stop character
Figure 1 — Code 39 symbol
4.3 Character encodation
4.3.1 Symbol character structure
Each symbol character comprises nine elements (five bars and four spaces) of which six are always
narrow (either three narrow bars and three narrow spaces, or five narrow bars and one narrow space)
and three are always wide (one wide space and two wide bars when there are three narrow bars, or
three wide spaces when there are five narrow bars). This parity feature enables character self‑checking
to be carried out.
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ISO/IEC DIS 16388:2022(E)
4.3.2 Symbol character assignments
Table 1 defines all the Code 39 character assignments.
Table 1 — Code 39 character assignments
ASCII
Char. Encodation Pattern B S B S B S B S B
Value
(decimal)
0 0 0 0 1 1 0 1 0 0 48
1 1 0 0 1 0 0 0 0 1 49
2 0 0 1 1 0 0 0 0 1 50
3 1 0 1 1 0 0 0 0 0 51
4 0 0 0 1 1 0 0 0 1 52
5 1 0 0 1 1 0 0 0 0 53
6 0 0 1 1 1 0 0 0 0 54
7 0 0 0 1 0 0 1 0 1 55
8 1 0 0 1 0 0 1 0 0 56
9 0 0 1 1 0 0 1 0 0 57
A 1 0 0 0 0 1 0 0 1 65
B 0 0 1 0 0 1 0 0 1 66
C 1 0 1 0 0 1 0 0 0 67
D 0 0 0 0 1 1 0 0 1 68
E 1 0 0 0 1 1 0 0 0 69
F 0 0 1 0 1 1 0 0 0 70
G 0 0 0 0 0 1 1 0 1 71
H 1 0 0 0 0 1 1 0 0 72
I 0 0 1 0 0 1 1 0 0 73
J 0 0 0 0 1 1 1 0 0 74
K 1 0 0 0 0 0 0 1 1 75
L 0 0 1 0 0 0 0 1 1 76
M 1 0 1 0 0 0 0 1 0 77
N 0 0 0 0 1 0 0 1 1 78
O 1 0 0 0 1 0 0 1 0 79
P 0 0 1 0 1 0 0 1 0 80
Q 0 0 0 0 0 0 1 1 1 81
R 1 0 0 0 0 0 1 1 0 82
S 0 0 1 0 0 0 1 1 0 83
T 0 0 0 0 1 0 1 1 0 84
U 1 1 0 0 0 0 0 0 1 85
V 0 1 1 0 0 0 0 0 1 86
W 1 1 1 0 0 0 0 0 0 87
X 0 1 0 0 1 0 0 0 1 88
Y 1 1 0 0 1 0 0 0 0 89
Z 0 1 1 0 1 0 0 0 0 90
hyphen 0 1 0 0 0 0 1 0 1 45
NOTE 1  S/S denotes the start and stop character, usually graphically represented as *.
NOTE 2  In the columns headed B and S, 0 represents a narrow element and 1 a wide element.
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ISO/IEC DIS 16388:2022(E)
Table 1 (continued)
ASCII
Char. Encodation Pattern B S B S B S B S B
Value
(decimal)
period 1 1 0 0 0 0 1 0 0 46
space 0 1 1 0 0 0 1 0 0 32
$ 0 1 0 1 0 1 0 0 0 36
/ 0 1 0 1 0 0 0 1 0 47
+ 0 1 0 0 0 1 0 1 0 43
% 0 0 0 1 0 1 0 1 0 37
S/S or * 0 1 0 0 1 0 1 0 0 none
NOTE 1  S/S denotes the start and stop character, usually graphically represented as *.
NOTE 2  In the columns headed B and S, 0 represents a narrow element and 1 a wide element.
4.3.3 Start and stop characters
The Code 39 start and stop character is usually depicted in human‑readable form by a * (asterisk). This
character shall not form part of the data encoded elsewhere in the symbol and shall not be transmitted
by the decoder.
The start character shall be positioned at the normal left end of the data symbol characters, separated
from the first bar of the leading data character by an intercharacter gap. The stop character shall be
positioned at the normal right end of the data symbol characters (including symbol check character if
present), separated from the final bar of the trailing data character by an intercharacter gap.
4.3.4 Optional symbol check character
Annex A defines the symbol check character position and calculation.
4.4 Dimensions
Code 39 symbology shall use the following nominal dimensions.
a) Width of narrow element (X): the X dimension of Code 39 symbols should be defined by the
application specification having due regard to the availability of equipment for the production and
reading of symbols and complying with the general requirements of the application. See 4.7.1.
b) Wide/narrow ratio (N): 2,0 : 1 to 3,0 : 1.
c) Width of intercharacter gap (I):
1) minimum: equal to X;
2) maximum:
for X < 0,287 mm: 5,3X;
for X ≥ 0,287 mm: 1,52 mm or 3X, whichever is greater.
d) Minimum width of quiet zone: 10X.
e) Recommended minimum bar code height for manual scanning: 5,0 mm or 15 % of symbol width
excluding quiet zones, whichever is greater.
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ISO/IEC DIS 16388:2022(E)
NOTE The width, W (in millimetres), of a Code 39 symbol, including quiet zones, can be calculated from the
following expression:
WC=+()23()NX+61++()CI +2Q
where
W is the symbol width;
C is the number of data characters (including symbol check character if used);
N is the wide/narrow ratio;
X is the width of a narrow element in millimetres;
l is the width of the intercharacter gap in millimetres;
Q is the width of the quiet zone in millimetres.
4.5 Reference decode algorithm
Bar code reading systems are designed to read imperfect symbols to the extent that practical
algorithms permit. This section describes the reference decode algorithm used in the computation of
the decodability value described in ISO/IEC 15416.
a) Confirm presence of a leading quiet zone.
b) For each symbol character (including start and stop characters):
1) Measure the total width of 5 bars and 4 spaces; call this S.
2) Compute a threshold value, T = S / 8.
3) Compare each element width for that character with the value T. If element width is greater
than T, assume element is wide; if not, assume element is narrow.
4) Determine if pattern of wide and narrow elements matches a valid character from the allowable
set.
c) The first symbol character read must be a start/stop character, from which the scan direction can
be deduced.
d) Continue character reading until a valid start/stop character is encountered.
e) Confirm presence of a trailing quiet zone.
4.6 Symbol quality
4.6.1 Test specification
In order to verify whether a symbol meets the specifications in this International Standard it shall
...