ISO/FDIS 6346

Freight containers -- Coding, identification and marking

Conteneurs pour le transport de marchandises -- Codage, identification et marquage

General Information

• Status: Published
• ICS: 55.180.10 - General purpose containers
• Technical Committee: ISO/TC 104/SC 4 - Identification and communication
• Drafting Committee: ISO/TC 104/SC 4/WG 1 - Coding, identification and marking (Revision of ISO 6346)
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 06-Dec-2021
• Completion Date: 06-Dec-2021

RELATIONS

• Revised: ISO 6346:1995 - Freight containers -- Coding, identification and marking
• Effective Date: 04-Dec-2021
• Revised: ISO 6346:1995/Amd 3:2012 - ISO 6346:1995/Amd 3:2012
• Effective Date: 04-Dec-2021

Standards Content (sample)

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 6346
ISO/TC 104/SC 4
Freight containers — Coding,
Secretariat: AFNOR
identification and marking
Voting begins on:
2021-12-06
Conteneurs pour le transport de marchandises — Codage,
identification et marquage
Voting terminates on:
2022-01-31
ISO/CEN PARALLEL PROCESSING
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 SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 6346:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2021
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ISO/FDIS 6346:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

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ISO/FDIS 6346:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 2

3 Terms and definitions .................................................................................................................................................................................... 2

4 Identification system and its associated marks ................................................................................................................. 2

4.1 Identification system ........................................................................................................................................................................ 2

4.1.1 General ........................................................................................................................................................................................ 2

4.1.2 Owner code ............................................................................................................................................................................. 2

4.1.3 Equipment category identifier ............................................................................................................................... 2

4.1.4 Serial number ........................................................................................................................................................................ 3

4.1.5 Check digit ................................................................................................................................................................................ 3

4.2 Identification marks .......................................................................................................................................................................... 3

5 Size and type codes and their associated marks ............................................................................................................... 3

5.1 Purpose ......................................................................................................................................................................................................... 3

5.2 Size and type codes ............................................................................................................................................................................ 3

5.2.1 General ........................................................................................................................................................................................ 3

5.2.2 Size: two alphanumeric characters .................................................................................................................... 3

5.2.3 Type: two characters ...................................................................................................................................................... 4

6 Operational marks ............................................................................................................................................................................................. 4

6.1 General ........................................................................................................................................................................................................... 4

6.2 Mandatory operational marks.................................................................................................................................................. 4

6.2.1 Maximum gross and tare masses ........................................................................................................................ 4

6.2.2 Air/surface container symbol ................................................................................................................................. 4

6.2.3 Warning sign of overhead electrical danger .............................................................................................. 5

6.2.4 Height mark for containers higher than 2,6 m (8 ft 6 in) ............................................................... 5

6.2.5 Width mark for containers with an overall width greater than 2 438 m

(8 ft). .............................................................................................................................................................................................. 5

6.3 Optional operational mark (maximum mass of payload) ................................................................................ 5

7 Physical display of marks ...........................................................................................................................................................................5

7.1 Size and colour of marks ................................................................................................................................................................ 5

7.2 Layout and location of marks .................................................................................................................................................... 6

7.2.1 Layout of marks ................................................................................................................................................................... 6

7.2.2 Location of marks .............................................................................................................................................................. 9

Annex A (normative) Determination of check digit ..........................................................................................................................11

Annex B (normative) Symbol to denote air/surface container .............................................................................................13

Annex C (normative) Sign warning of overhead electrical danger ..................................................................................14

Annex D (normative) Size code designation .............................................................................................................................................15

Annex E (normative) Type Code designation ...........................................................................................................................................17

Annex F (normative) Height marks for containers higher than 2,6 m (8 ft 6 in) ...............................................23

Annex G (normative) Overall width marks for containers wider than 2 438 m (8 ft) .................................24

Bibliography .............................................................................................................................................................................................................................25

iii
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ISO/FDIS 6346:2021(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/TC 104, Freight containers, Subcommittee

SC 4, Identification and communication, in collaboration with European Committee for Standardization

(CEN) Technical Committee CEN/TC 119, Intermodal loading units and Cargo securing (ILUCS), in

accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).

This fourth edition cancels and replaces the third edition (ISO 6346:1995), which has been technically

revised. It also incorporates the Amendment ISO 6346:1995/Amd 3:2012.
The main changes are as follows:

— Incorporation of previous amendments to the standard to include the provision of markings to

identify containers with reduced stacking or racking;
— Inclusion of new markings to identify over width containers;

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.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 6346:2021(E)
Freight containers — Coding, identification and marking
1 Scope

1.1 This document provides a system for the identification and presentation of information about

freight containers. The identification system is intended for general application, for example in

documentation, control and communications (including automatic data processing systems), as well as

for display on the containers themselves.

The methods of displaying identification and certain other data (including operational data) on

containers by means of permanent marks are included.
1.2 This document specifies:

a) a container identification system, with an associated system for verifying the accuracy of its use,

having:

— mandatory marks for the presentation of the identification system for visual interpretation,

and

— features to be used in optional Automatic Equipment Identification (AEI) and electronic data

interchange (EDI);

b) a coding system for data on container size and type, with corresponding marks for their display;

c) operational marks, both mandatory and optional;
d) physical presentation of marks on the container.

1.3 The terms “mandatory” and “optional” in this document are used to differentiate those ISO

marking provisions which shall necessarily be fulfilled by all containers from those which are not

required of all containers. The optional marks are included to further comprehension and promote

uniform application of the optional mark. If a choice has been made to display an optional mark, the

provisions laid down in this document relating to the mark shall be applied. The terms “mandatory”

and “optional” do not refer to requirements of any regulatory body.

1.4 This document applies to all freight containers covered by International Standards ISO 668, parts

1 to 5 of ISO 1496, ISO 8323 and should, wherever appropriate and practicable, be applied:

— to containers other than those covered by the International Standards mentioned in Clause 2;

— to container-related and/or detachable equipment.

NOTE 1 Containers marked according to previous editions of ISO 6346 need not be re-marked.

1.5 This document does not cover temporary operational marks of any kind, permanent marks,

data plates, etc. which may be required by intergovernmental agreements, national legislation or

nongovernmental organizations.

NOTE 2 Some of the major international conventions whose container-marking requirements are not covered

in this document are as follows:

— International Convention for Safe Containers (1972, as amended) (CSC), International Maritime Organization

(IMO);
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ISO/FDIS 6346:2021(E)

— Customs Convention on Containers 1956 and 1972, related to temporary admission and transport under

customs seal.

— Convention on Temporary Admission (Istanbul, 26 June 1990), related to temporary admission.

It should not be assumed that this list is exhaustive.

This document does not cover the display of technical data on tank containers (see ISO 1496-3), nor

does it, in any way, include identification marks or safety signs for items of cargo which may be carried

in freight containers.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.

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 Identification system and its associated marks
4.1 Identification system
4.1.1 General

The identification system shall consist only of the following elements, all of which shall be included:

— owner code: three letters (see 4.1.2);
— equipment category identifier: one letter (see 4.1.3);
— serial number: six numerals (see 4.1.4);
— check digit: one numeral (see 4.1.5).
4.1.2 Owner code
Reference (1) in Figures 1 to 4

The container owner’s code shall consist of three capital letters, shall be unique and shall be registered

with the Registration Authority.

The name and contact information of the Registration Authority for this document can be found at

www .iso .org/ maintenance _agencies.
4.1.3 Equipment category identifier
Reference (2) in Figures 1 to 4

The equipment category identifier consists of one capital letter of the Latin alphabet as follows:

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ISO/FDIS 6346:2021(E)
— U for all freight containers;
— J for detachable freight container-related equipment;
— Z for trailers and chassis.
4.1.4 Serial number
Reference (3) in Figures 1 to 4

The container serial number shall consist of six Arabic numerals. If the series of significant numerals

does not total six, they shall be preceded by sufficient zeroes to make up six numerals (for example, if

the series of significant numerals is 1234, the serial number is 001234).
4.1.5 Check digit
Reference (4) in Figures 1 to 4

The check digit provides a means of validating the transmission accuracy of the owner code and serial

number and shall be determined as in Annex A. The check digit shall validate the owner code, equipment

category identifier and serial number of the container.
4.2 Identification marks

The use of marks in accordance with the identification system specified in 4.1, i.e. owner code,

equipment category identifier, serial number and check digit, is mandatory for freight containers and

recommended for all equipment as stated in 4.1.3. The characteristics (size, shape, layout, etc.) detailed

in 7.1 and 7.2.1 shall be displayed as nearly as practicable in accordance with Clause 7, i.e., legible to the

human eye.
5 Size and type codes and their associated marks
5.1 Purpose

The type and main external dimensions of the container shall be identified with codes marked on the

container. Only those freight containers which conform with both the ISO top-handling capability and

structural stacking requirements set forth in ISO 1496 shall be marked with size and type codes in

accordance with 5.2.2 and 5.2.3.
5.2 Size and type codes
5.2.1 General

This information is mandatory for the marking of containers covered by the International Standards

listed in Clause 2 and shall be coded as in 5.2.2 and 5.2.3.

The size and type codes, when displayed on the container, shall be used as a whole, i.e., the information

must not be broken into its component parts.
The size and type codes shall be displayed in accordance with Clause 7.
5.2.2 Size: two alphanumeric characters
Reference (5) in Figures 1 to 4

The container size (i.e. external dimensions) shall be indicated by two characters as follows:

— First character: numeric or alphabetic character representing the length.
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ISO/FDIS 6346:2021(E)

— Second character: numeric or alphabetic character representing the width and the height.

These two characters shall be determined in accordance with Annex D.
5.2.3 Type: two characters
Reference (6) in Figures 1 to 4

The container type and main characteristics shall be indicated by two characters as follows:

— First character: alphabetic character representing the container type.

— Second character: numeric or alphabetic character representing main characteristics related to the

container type.
These two characters shall be selected in accordance with Annex E.

NOTE For the purpose of exchanging data when indication of the main characteristics is not essential, the

“type group code designation” as shown in Annex E can be used.
6 Operational marks
6.1 General

The marks in this section are not intended to correspond to any particular code (e.g., for use in data

transmission or any other purpose). They are solely intended as markings for use on freight containers

to convey certain information or give visual warnings.
6.2 Mandatory operational marks
6.2.1 Maximum gross and tare masses
The maximum gross and tare masses shall be marked on a container as:
MAX GROSS 00 000 kg
00 000 lb
TARE 00 000 kg
00 000 lb

For safety reasons, containers tested in conformance with the approved methods specified in that part

of ISO 1496 applicable to the type of container in question, i.e., parts 1, 2, 3, 4 or 5 of ISO 1496, shall be

uniformly marked with the maximum gross mass used for those tests.

Furthermore, the “maximum gross mass” marked on the container in accordance with this document

shall be identical to that shown on the CSC Safety Approval Plate.

As indicated above, the masses shall be expressed in both kilograms (kg) and pounds (lb).

NOTE 1 kg = 2 204 lb.
6.2.2 Air/surface container symbol
All air/surface containers shall display the symbol specified in Annex B.
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ISO/FDIS 6346:2021(E)
6.2.3 Warning sign of overhead electrical danger

All containers equipped with ladders shall display a warning sign in accordance with the details given

in Annex C.
6.2.4 Height mark for containers higher than 2,6 m (8 ft 6 in)

All containers higher than 2,6 m (8 ft 6 in) shall bear the following mandatory marks:

a) on both sides, a height mark similar to that described in Annex F;

b) an area of alternating black and yellow stripes on the top members of each end frame and side wall

at each corner adjacent to the corner fitting, of 300 mm (12 in) minimum length, that can be seen

from the ground or from the top. See Figure 5.

In addition, any other optional marks, such as a mirror image of the mark described in Annex F, may be

displayed at any convenient location (e.g., front wall).

6.2.5 Width mark for containers with an overall width greater than 2 438 m (8 ft).

All containers with an overall width greater than 2 438 m (8 ft) shall bear a mark similar to that

described in Annex G on the ends and the roof at both ends.

Where there is insufficient space to fit the marking on the ends or the roof, for example on tank

containers, the marking shall be as wide as is practicable on the ends and may be omitted on the roof.

6.3 Optional operational mark (maximum mass of payload)

It is common industry practice to mark containers with maximum payload in addition to the maximum

gross and tare masses.

If used, the maximum mass of payload should be marked on a container in accordance with the

requirements of 6.2.1, positioned after the maximum gross and tare masses as follows:

7 Physical display of marks
7.1 Size and colour of marks

The letters and numerals of the owner code, equipment category identifier, serial number and check

digit shall be not less than 100 mm (4 in) high.

The letters and numerals for MAX GROSS, TARE and, when used, PAYLOAD shall be not less than 50 mm

(2 in) high.

All characters shall be of proportionate width and thickness, they shall be durable and in a colour

contrasting with that of the container.
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ISO/FDIS 6346:2021(E)
7.2 Layout and location of marks

The requirements of this clause are particularly applicable to containers of the “closed box” type. For

containers of other types, all possible practicable steps should be taken to follow the marking layout

and location given for the “closed box” type of container.
7.2.1 Layout of marks
7.2.1.1 General

The layout of the owner code, equipment category identifier, serial number and check digit on containers

shall preferably be in one single horizontal line (see Figure 1). Where constructional features of the

container dictate otherwise, the layout may be vertical (see Figure 2).

The layout of size and type codes should, as far as practicable, be in a single horizontal line underneath

the horizontal line giving the owner code, equipment category identifier, serial number and check digit

(see Figure 1).

When the owner code, equipment category identifier, serial number and check digit are displayed

vertically, the size and type codes should be placed adjacent to the other mandatory marks (see Figure 2

and Figure 3).

If, on some special-purpose containers, a fully horizontal or fully vertical layout is not possible, the

layout of the other mandatory identification marks shall be maintained in the horizontal or vertical

groupings as specified below (see Figure 3 and Figure 4).

On those special-purpose containers where a fully horizontal or fully vertical layout is not possible and

the layout of the other mandatory identification marks is horizontal, the size and type codes should be

placed beneath the other mandatory marks (see Figure 4).
The size and type codes should be used as a whole (see 5.2).

The owner code and equipment category identifier shall be joined and shall be separated from the serial

number by at least one character space. The serial number shall be separated from the check digit by

one character space and the check digit shall be displayed in a box.
EXAMPLE

A general purpose container in accordance with ISO 1496, having passive vents at the upper part of the cargo

space, a length of 6 068 mm, a width of 2 438 mm, a height of 2 591 mm, having a unique registered owner code

of ABZ, an equipment category identifier of U and a serial number of 001234 will have the layout as shown in

Figure 1 to Figure 4.
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ISO/FDIS 6346:2021(E)
Key
1 owner’s code
2 category identifier
3 serial number
4 check digit
5 size code
6 type code
Figure 1 — Mandatory identification marks - preferred horizontal layout
Key
1 owner’s code
2 category identifier
3 serial number
4 check digit
5 size code
6 type code
Figure 2 — Mandatory identification marks - preferred vertical layout
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ISO/FDIS 6346:2021(E)
Key
1 owner’s code
2 category identifier
3 serial number
4 check digit
5 size code
6 type code

Figure 3 — Mandatory identification marks - Alternative (multiple column) vertical layout

Key
1 owner’s code
2 category identifier
3 serial number
4 check digit
5 size code
6 type code

Figure 4 — Mandatory identification marks - Alternative horizontal grouping layout

7.2.1.2 Mandatory operational marks
The layout of maximum gross and tare masses shall be as stated in 6.2.1.
The layout of the air/surface container symbol shall be as shown in Annex B.

The layout of the sign warning of overhead electrical danger shall be as shown in Annex C.

The layout of the height mark for containers having a height greater than 2,6 m shall be as stated in

Annex F.
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ISO/FDIS 6346:2021(E)

The layout for the width mark for containers having a width greater than 2 438 m shall be as stated in

Annex G.
7.2.1.3 Optional operational mark (maximum mass of payload)
Where marked, the layout of payload shall be as stated in 6.3.
7.2.2 Location of marks
7.2.2.1 Mandatory identification marks

The mandatory marks of 4.1 and 5.2, i.e., owner code, equipment category identifier, serial number,

check digit, and size and type codes, shall be positioned on the container as far as practicable as shown

in Figure 5.

Containers with reduced stacking or reduced racking strength shall have size type code marks on the

front (blind end) and on the roof at either end.
7.2.2.2 Operational marks

The mandatory operational marks of 6.2.1, i.e., maximum gross and tare masses, shall be positioned on

the container as far as practicable as shown in Figure 5.
The location of the air/surface container symbol shall be as given in Annex B.

The location of the symbol warning of overhead electrical danger shall be as given in Annex C.

The location of the height warning symbol shall be as given in Annex F and shown in Figure 5.

The location of the width mark shall be as given in Annex G and shown in Figure 5.

The optional operational mark of 6.3, i.e., maximum payload or net mass, shall be positioned on the

container as far as practicable as shown in Figure 5.
7.2.2.3 Other marks and devices

Marks other than those stipulated by this document shall be displayed on the container so that they do

not in any way interfere with the marks described in this document.

For the Automatic Equipment Identification (AEI) system, the AEI tag shall be positioned on the

container as specified in ISO 10374.
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ISO/FDIS 6346:2021(E)
Key
1 blind / front end 3 container side
2 door / rear end 4 automatic equipment identifier tag

NOTE 1 Black and yellow stripes adjacent to the corner fitting can be reduced to a length of 300 mm min.

NOTE 2 Size and type marking on the roof and on the front (blind end) are optional except for containers with

reduced stacking and/or racking.
NOTE 3 Mounting of AEI tag is optional.
NOTE 4 “PAYLOAD” marking is optional.
Figure 5 — Location of mandatory and optional marks
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ISO/FDIS 6346:2021(E)
Annex A
(normative)
Determination of check digit

The check digit of a container identification system is determined by following the procedure outlined

in A.1 to A.4. A sample calculation is presented in A.5.
A.1 Numerical equivalents of container owner code, category identifier and
serial number

Each letter of the owner code, the equipment category identifier and each numeral of the serial number

all be con
...