IEC 61406-1:2022

IEC 61406-1 ®
Edition 1.0 2022-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Identification link –
Part 1 : General requirements
Lien d’identification –
Partie 1 : Exigences générales

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IEC 61406-1 ®
Edition 1.0 2022-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Identification link –
Part 1 : General requirements
Lien d’identification –
Partie 1 : Exigences générales

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 35.240.15 ISBN 978-2-8322-5605-3

– 2 – IEC 61406-1:2022 © IEC 2022
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 10
2 Normative references . 10
3 Terms, abbreviated terms and definitions . 11
4 Identification Link string . 12
4.1 ILS-1: Global uniqueness . 12
4.1.1 Requirement . 12
4.1.2 Rationale and supplemental guidance. 12
4.2 ILS-2: Link to additional information . 13
4.2.1 Requirement . 13
4.2.2 Rationale and supplemental guidance. 13
4.3 ILS-3: No reuse. 13
4.3.1 Requirement . 13
4.3.2 Rationale and supplemental guidance. 14
4.4 ILS-4: No altering . 14
4.4.1 Requirement . 14
4.4.2 Rationale and supplemental guidance. 14
4.5 ILS-5: String length . 14
4.5.1 Requirement . 14
4.5.2 Rationale and supplemental guidance. 14
4.6 ILS-6: URL syntax . 14
4.6.1 Requirement . 14
4.6.2 Rationale and supplemental guidance. 14
4.7 ILS-7: Allowed characters . 15
4.7.1 Requirement . 15
4.7.2 Rationale and supplemental guidance. 15
4.8 ILS-8: Uppercase and lowercase characters . 15
4.8.1 Requirement . 15
4.8.2 Rationale and supplemental guidance. 15
4.9 ILS-9: No character-combinations with special functions . 16
4.9.1 Requirement . 16
4.9.2 Rationale and supplemental guidance. 16
5 Identification Link with 2D symbol . 16
5.1 2D-1: When marking with 2D symbol . 16
5.1.1 Requirement . 16
5.1.2 Rationale and supplemental guidance. 16
5.2 2D-2: 2D symbol content . 17
5.2.1 Requirement . 17
5.2.2 Rationale and supplemental guidance. 17
5.3 2D-3: Symbology . 17
5.3.1 Requirement . 17
5.3.2 Rationale and supplemental guidance. 17
5.4 2D-4: Module size . 17
5.4.1 Requirement . 17
5.4.2 Rationale and supplemental guidance. 17

5.5 2D-5: Quiet zone . 17
5.5.1 Requirement . 17
5.5.2 Rationale and supplemental guidance. 18
5.6 2D-6: Error correction . 18
5.6.1 Requirement . 18
5.6.2 Rationale and supplemental guidance. 18
5.7 2D-7: Label print quality . 18
5.7.1 Requirement . 18
5.7.2 Rationale and supplemental guidance. 18
5.8 2D-8: Direct part marking print quality . 18
5.8.1 Requirement . 18
5.8.2 Rationale and supplemental guidance. 19
5.9 2D-9: Durability of the 2D marking . 19
5.9.1 Requirement . 19
5.9.2 Rationale and supplemental guidance. 19
5.10 2D-10: Frame . 19
5.10.1 Requirement . 19
5.10.2 Rationale and supplemental guidance. 19
5.11 2D-11: Positive image . 20
5.11.1 Requirement . 20
5.11.2 Rationale and supplemental guidance. 20
5.12 2D-12: Location of the 2D symbol . 21
5.12.1 Requirement . 21
5.12.2 Rationale and supplemental guidance. 21
6 Near Field Communication for the Identification Link . 22
6.1 NFC-1: When marking with NFC . 22
6.1.1 Requirement . 22
6.1.2 Rationale and supplemental guidance. 22
6.2 NFC-2: Air interface standards . 22
6.2.1 Requirement . 22
6.2.2 Rationale and supplemental guidance. 22
6.3 NFC-3: Data format and content . 23
6.3.1 Requirement . 23
6.3.2 Rationale and supplemental guidance. 23
6.4 NFC-4: Data consistency . 23
6.4.1 Requirement . 23
6.4.2 Rationale and supplemental guidance. 23
6.5 NFC-5: Protection classes and approvals . 23
6.5.1 Requirement . 23
6.5.2 Rationale and supplemental guidance. 23
6.6 NFC-6: Durability . 24
6.6.1 Requirement . 24
6.6.2 Rationale and supplemental guidance. 24
6.7 NFC-7: Write protection . 24
6.7.1 Requirement . 24
6.7.2 Rationale and supplemental guidance. 24
6.8 NFC-8: Tag location for use in installed state . 24
6.8.1 Requirement . 24
6.8.2 Rationale and supplemental guidance. 24

– 4 – IEC 61406-1:2022 © IEC 2022
6.9 NFC-9: Tag position relative to existing marking for identification . 25
6.9.1 Requirement . 25
6.9.2 Rationale and supplemental guidance. 25
6.10 NFC-10: Tag position relative to neighbouring tags . 25
6.10.1 Requirement . 25
6.10.2 Rationale and supplemental guidance. 25
6.11 NFC-11: Generic RFID Emblem in frame . 25
6.11.1 Requirement . 25
6.11.2 Rationale and supplemental guidance. 26
6.12 NFC-12: RFID Emblem visibility . 26
6.12.1 Requirement . 26
6.12.2 Rationale and supplemental guidance. 26
6.13 NFC-13: RFID Emblem position relative to tag . 26
6.13.1 Requirement . 26
6.13.2 Rationale and supplemental guidance. 27
Annex A (normative) Overview of characters permitted for the IL string . 28
Annex B (informative) Examples of Identification Link strings . 31
B.1 Examples: URL syntax according to IETF RFC 3986 with restrictions
according to this document . 31
B.2 Examples: Parameters with data identifiers according to ISO/IEC 15418 . 33
Annex C (informative) 2D symbol examples and layout considerations . 35
C.1 Choice of symbology . 35
C.2 Square and rectangular symbols . 35
C.3 Selection of corner for triangle when using QR Code . 36
C.4 Symbols not centered in the frame . 36
C.5 Layout example when space is not sufficient . 37
Annex D (informative) 2D symbols on curved surfaces . 38
Annex E (informative) Duplicates of the Identification Link . 39
Annex F (informative) Search Engine friendliness . 40
Annex G (informative) Cybersecurity aspects . 41
Annex H (informative) IL string as IRDI . 42
Bibliography . 43

Figure 1 – Example of an IL linking a physical object to information associated with it . 13
Figure 2 – Frame around the 2D symbol . 20
Figure 3 – Comparison of a 2D symbol as negative and normal positive image . 20
Figure 4 – Representation of an IL on a dark background . 21
Figure 5 – marking of an NFC tag as an IL . 26
Figure C.1 – IL size may vary depending on the used symbology . 35
Figure C.2 – IL with square and rectangular Data Matrix . 36
Figure C.3 – IL with 2D symbols not centered in the frame . 36
Figure C.4 – IL with 2D symbols quiet zone below 4 modules on 2 sides . 37

Table A.1 – List of ASCII Code Characters permitted as this standard to create an IL . 29
Table B.1 – Structure of example a) . 31
Table B.2 – Structure of example b) . 31

Table B.3 – Structure of example c) . 31
Table B.4 – Structure of example d) . 32
Table B.5 – Structure of example e) . 32
Table B.6 – Structure of example f) . 32
Table B.7 – Structure of example g) . 33
Table B.8 – Structure of example h) . 33
Table B.9 – Structure of example a) . 34
Table B.10 – Structure of example b) . 34
Table D.1 – Recommended maximum radii when using QR Codes . 38

– 6 – IEC 61406-1:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IDENTIFICATION LINK
Part 1: General requirements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 61406-1 has been prepared by subcommittee 65E: Devices and integration in enterprise
systems, of IEC technical committee 65: Industrial-process measurement, control and
automation. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
65E/845/CDV 65E/905/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available

at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 61406 series, published under the general title Identification link,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

– 8 – IEC 61406-1:2022 © IEC 2022
INTRODUCTION
Every year, industry purchases hundreds of millions of items of technical equipment – referred
to here as physical objects – for setting up new production facilities and maintaining existing
ones. When applying this standard, these physical objects can be simply and unambiguously
identified by using a standardized Identification Link (IL), attached for example on the
nameplate. This means that all information relating to the physical object can be identified in
various IT systems and then called up, edited and stored as necessary across all processes
from storage and retrieval to assembly, maintenance, inspection, repair and disassembly. This
is an invaluable advantage in all these processes. The manufacturer in turn can link all
information such as drawings, operating instructions and spare part lists to this IL in its systems.
Users, e.g. owners or operators, can do the same with their information in their systems. In
communication between the manufacturer and user, this IL alone then suffices for both parties
to find and exchange all the information they need about a physical object throughout its
lifecycle. This IL is therefore a prerequisite for easy accessing and maintaining information in
the physical object’s digital twin.
Previous standards for machine-readable identification of physical objects essentially describe
how the traditional identification features (manufacturer, product number, serial number) can
be stored in a machine-readable way using standardized syntax (e.g. as per ISO/IEC 15434 [6])
and semantics (e.g. as per ISO/IEC 15418 [7]) so that the strings used for identification
according to these standards can be analyzed (parsed) and processed across all manufacturers
using suitable software. These regulations allow a great variety of identifiers and technologies
to be used, some of which can be highly complex, depending on the chosen solution. This
means that in the relationship between the manufacturer and the user, which parts of these
regulations and which of the identification methods specified in them are to be used needs to
be determined. A universally usable identification by the manufacturer is not possible without
consulting the respective user. The identification options listed in these regulations also always
require analysis of the character string and the information encoded in it using suitable software,
which involves much greater requirements for further processing. Furthermore, for industrial
applications such as in the process manufacturing industry, there are special requirements for
the long-term legibility and reliability of markings in the harsh conditions of industrial
environments.
Production systems, e.g. in the process manufacturing industry, usually consist of several
thousand individual physical objects. Each of these physical objects must be uniquely identified
during all steps and processes in its lifecycle by both the manufacturer and the user. On the
part of the manufacturer, this identification starts during the production of the physical object,
and continues during its packaging and shipping. On the part of user, this process continues
with the receipt, storage and retrieval of the physical object, carries on through installation,
commissioning, operation, inspection, maintenance, repair and disassembly, and finally ends
when it is scrapped.
The manufacturer usually provides each physical object with an identifier that allows it to be
uniquely identified. This identification of the physical object usually takes place using a
nameplate.
The product type of the physical object can generally be clearly identified using the information
on the nameplate. If it is a serialized physical object, which means a serial number is present
on the nameplate, then it can also be identified as a single, distinguishable instance of a model.
However, in practice this identification of physical objects on a nameplate often cannot be read
and used automatically. This is a serious drawback to optimizing and in particular automating
identification in all work processes. The reason for this is that the characteristics of a nameplate
such as the content, designation, layout and fonts vary greatly according to the physical object
and the manufacturer. The same applies to the physical properties of the nameplate, such as
the material and the process for producing the graphic content (e.g. printing, etching, engraving,
laser marking etc.).
This document does not try to standardize nameplates or physical properties of nameplates,
due to the widely differing requirements of manufacturers and users and the vast variety of
objects.
Optimizing and automating the identification of a physical object merely requires a unique
machine-readable ID attached to the object.
Linking to information on the internet with a URL in a 2D symbol or NFC tag on the physical
object is more and more used.
This Identification Link covers in a simple, monomorphic and single solution both major use
cases for machine readable product marking, the unique identification and the link to data on
the internet.
– 10 – IEC 61406-1:2022 © IEC 2022
IDENTIFICATION LINK
1 Scope
This part of IEC 61406 specifies minimum requirements for a globally unique identification of
physical objects which also constitutes a link to its related digital information. This identification
is designated hereinafter as "Identification Link" (IL), with the encoded data designated as IL
string. The IL string has the data-format of a link (URL). The IL is machine-readable and is
attached to the physical object in a 2D symbol or NFC tag.
The requirements in this document apply to physical objects
• that are provided by the manufacturer as an individual unit,
• and that have already been given a unique identity by the manufacturer.
This document does not specify any requirements on the content and the layout of
nameplates/typeplates (e.g. spatial arrangement, content of the plain texts, approval symbols
etc.).
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.
IEC 60050-351, International Electrotechnical Vocabulary (IEV) – Part 351: Control technology
ISO/IEC 8859-1, Information technology – 8-bit single-byte coded graphic character sets –
Part 1: Latin alphabet No. 1
ISO/IEC 14443-1, Cards and security devices for personal identification – Contactless proximity
objects – Part 1: Physical characteristics
ISO/IEC 14443-2, Cards and security devices for personal identification – Contactless proximity
objects – Part 2: Radio frequency power and signal interface
ISO/IEC 14443-3, Cards and security devices for personal identification – Contactless proximity
objects – Part 3: Initialization and anticollision
ISO/IEC 14443-4, Cards and security devices for personal identification – Contactless proximity
objects – Part 4: Transmission protocol
ISO/IEC 15415, Information technology – Automatic identification and data capture techniques
– Bar code symbol print quality test specification – Two-dimensional symbols
ISO/IEC 15693-1, Cards and security devices for personal identification – Contactless vicinity
objects – Part 1: Physical characteristics
ISO/IEC 15693-2, Cards and security devices for personal identification – Contactless vicinity
objects – Part 2: Air interface and initialization

ISO/IEC 15693-3, Cards and security devices for personal identification – Contactless vicinity
objects – Part 3: Anticollision and transmission protocol
ISO/IEC 16022, Information technology – Automatic identification and data capture techniques
– Data Matrix bar code symbology specification
ISO/IEC 19762, Information technology – Automatic identification and data capture (AIDC)
techniques – Harmonized vocabulary
ISO/IEC 18004, Information technology – Automatic identification and data capture techniques
– QR Code bar code symbology specification
ISO/IEC 29158, Information technology – Automatic identification and data capture techniques
– Direct Part Mark (DPM) Quality Guideline
ISO/IEC 29160, Information technology – Radio frequency identification for item management
– RFID Emblem
ISO 13849-1, Safety of machinery – Safety-related parts of control systems – Part 1: General
principles for design
IETF RFC 3986:2005, Uniform Resource Identifier (URI): Generic Syntax
3 Terms, abbreviated terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-351,
ISO/IEC 19762 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
data carrier
device or medium used to store data as a relay mechanism in an AIDC system
Note 1 to entry: Bar code, OCR character string and RF tag are examples of data carriers.
[SOURCE: ISO/IEC 19762:2016, 01-01-59]
3.2
Identification Link
IL
combination of 2D symbol or NFC tag and contained IL string
3.3
Identification Link string
IL string
data string in URL syntax which is the globally unique identification of a physical object and
points to related information on the internet
Example: https://www.domain-abc.com/sd09fqw4?1P=productcode&S=serialnumber

– 12 – IEC 61406-1:2022 © IEC 2022
3.4
manufacturer
company or organization with ultimate responsibility for the compliance of the physical object
with the appropriate standard or standards and to provide the product information
3.5
user
organization or person that is the owner or operator of the physical object
3.6
physical object
technical equipment such as vessels, units, machines, electronic devices and components,
assemblies, batteries, components, spare parts etc.
3.7
RFID Emblem
graphical symbol specified in ISO/IEC 29160 to inform users of the presence of RFID
3.8
symbology
standard means of representing data in optically machine readable form
Note 1 to entry: Each symbology specification sets out its particular rules of composition or symbol architecture.
[SOURCE: ISO/IEC 19762:2016, 02-01-02]
4 Identification Link string
4.1 ILS-1: Global uniqueness
4.1.1 Requirement
The IL string shall be a globally unique string that is assigned to only one physical object.
4.1.2 Rationale and supplemental guidance
The manufacturer and the user have an interest in unambiguously linking a physical object to
data accrued during its lifecycle using machine reading processes. The reasons for this might
include the following:
• If measures are carried out on a physical object, it must be unambiguously identified in order
to rule out any confusion with other physical objects which would endanger the physical
object itself, the system it is installed in, human beings or the environment.
• Any consistent and clear inventory management depends on unambiguous identification.
Figure 1 shows an example of the role of the globally unique IL for linking a physical object to
various data and information.
Figure 1 – Example of an IL linking a physical object to information associated with it
Examples of information possibly associated to the physical object are:
• information from the manufacturer such as operating instructions, drawings, spare parts lists
and calibration records;
• operating data such as speeds, power consumption and pressures;
• models such as function and simulation models;
• maintenance and inventory management data.
This information is required in many processes during the lifecycle of the physical object.
Simplifying access to this information using an IL is thus of significant benefit.
4.2 ILS-2: Link to additional information
4.2.1 Requirement
The IL string shall lead to additional information in digital form related to the physical object.
4.2.2 Rationale and supplemental guidance
In addition to identifying the physical object, the IL is also able to link to information pertaining
to the object in the manufacturer and the user systems, as well as in other systems such as
cloud-based third-party systems and to further information provided via the Internet.
NOTE This document does not specify requirements on format and content of the information provided.
4.3 ILS-3: No reuse
4.3.1 Requirement
Once an IL string has been assigned to a physical object, it shall not be reused for any another
physical object, even after the maximum lifetime of the physical object has expired.

– 14 – IEC 61406-1:2022 © IEC 2022
4.3.2 Rationale and supplemental guidance
An IL string is always associated with the one physical object to which it was originally assigned,
even after the end of life of that object.
4.4 ILS-4: No altering
4.4.1 Requirement
Once an IL string has been assigned to a physical object, it shall not be altered.
4.4.2 Rationale and supplemental guidance
An IL string is always associated with the one physical object to which it was originally assigned,
even after the end of life of that object.
4.5 ILS-5: String length
4.5.1 Requirement
The length of the IL sting shall not exceed 255 characters.
4.5.2 Rationale and supplemental guidance
The limit of 255 characters results from 8-bit data types in databases, as 2 = 256, which are
still relevant in some legacy applications.
In practice, it may be necessary to encode numerous or lengthy pieces of information in the IL
string. However, to make the IL string easy to place, to scan and to display and to use in brown
field legacy systems of the users, it must be as short as possible. Space for large 2D symbols
is typically very limited, especially on front panels or nameplates, and manufacturers typically
make strong efforts to reduce the content of the 2D symbol as much as possible.
It is recommended that external constraints are checked before creating strings longer than 72
characters.
NOTE 1 The largest rectangular Data Matrix code according to ISO/IEC 16022, with 16 x 48 cells, has the data
capacity of 72 alphanumeric characters.
NOTE 2 The shorter the length of the IL-string, the less risk there is of length conflicts with field limitations of the
IT-systems of business partners.
NOTE 3 Including a digital signature according to ISO/IEC 20248 [10] in the IL string increases the string-length by
around 120 additional characters.
4.6 ILS-6: URL syntax
4.6.1 Requirement
The IL string shall use the URL syntax according to IETF RFC 3986, with the exception that
scheme ("https") and "://www." may be omitted.
4.6.2 Rationale and supplemental guidance
The URL syntax is in common use and well defined. The domain name is unique by definition.
Apart linking to information on the internet, this syntax is also suitable for representing
information from the manufacturer such as the model name, serial number, date of manufacture.
This can be done without excessive data overheads, as for example when using XML.
Not all valid URL strings according to IETF RFC 3986 are allowed for the IL string. See ILS-5,
ILS-7, ILS-8 and ILS-9 with restrictions.

NOTE 1 Examples are provided in Annex B.
NOTE 2 This document does not specify any semantic requirements (see Annex F).
NOTE 3 The ULR-syntax is critical in regard to cybersecurity (see Annex G).
4.7 ILS-7: Allowed characters
4.7.1 Requirement
Only the following ASCII characters shall be used in the IL string:
All reserved characters according to IETF RFC 3986:2005, 2.2. These are:
• gen-d
...