EN IEC 81346-14:2026

SLOVENSKI STANDARD
01-oktober-2026
Industrijski sistemi, inštalacije in oprema ter industrijski izdelki - Načela
strukturiranja in referenčne oznake - 14. del: Proizvodni in predelovalni sistemi
(IEC 81346-14:2026)
Industrial systems, installations and equipment and industrial products - Structuring
principles and reference designations - Part 14: Manufacturing and processing systems
(IEC 81346-14:2026)
Industrielle Systeme, Anlagen und Ausrüstungen und Industrieprodukte -
Strukturierungsprinzipien und Referenzkennzeichnung - Teil 14: Fertigungssysteme (IEC
81346-14:2026)
Systèmes, installations et équipements industriels, et produits industriels - Principes de
structuration et désignations de référence - Partie 14: Systèmes de fabrication et de
traitement (IEC 81346-14:2026)
Ta slovenski standard je istoveten z: EN IEC 81346-14:2026
ICS:
01.110 Tehnična dokumentacija za Technical product
izdelke documentation
29.020 Elektrotehnika na splošno Electrical engineering in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 81346-14

NORME EUROPÉENNE
EUROPÄISCHE NORM July 2026
ICS 01.110
English Version
Industrial systems, installations and equipment and industrial
products - Structuring principles and reference designations -
Part 14: Manufacturing and processing systems
(IEC 81346-14:2026)
Systèmes, installations et équipements industriels, et Industrielle Systeme, Anlagen und Ausrüstungen und
produits industriels - Principes de structuration et Industrieprodukte - Strukturierungsprinzipien und
désignations de référence - Partie 14: Systèmes de Referenzkennzeichnung - Teil 14: Fertigungssysteme
fabrication et de traitement (IEC 81346-14:2026)
(IEC 81346-14:2026)
This European Standard was approved by CENELEC on 2026-06-23. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 81346-14:2026 E

European foreword
The text of document 3/1767/FDIS, future edition 1 of IEC 81346-14, prepared by TC 3
"Documentation, graphical symbols and representations of technical information" was submitted to the
IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 81346-14:2026.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-07-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-07-31
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document is read in conjunction with EN IEC 81346-1:2022.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 81346-14:2026 was approved by CENELEC as a European
Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 81346-1 2022 Industrial systems, installations and EN IEC 81346-1 2022
equipment and industrial products -
Structuring principles and reference
designations - Part 1: Basic rules
IEC 81346-2 — Industrial systems, installations and EN IEC 81346-2 —
equipment and industrial products -
Structuring principles and reference
designations - Part 2: Classification of
objects and codes for classes
Under preparation. Stage at time of publication: IEC FDIS 81346-2:2026.
IEC 81346-14
Edition 1.0 2026-05
INTERNATIONAL
STANDARD
HORIZONTAL PUBLICATION
Industrial systems, installations and equipment and industrial products -
Structuring principles and reference designations -
Part 14: Manufacturing and processing systems
ICS 01.110  ISBN 978-2-8327-1233-7

IEC 81346-14: 2026-05(en)
IEC 81346-14:2026 © IEC 2026
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 General concepts . 9
4.1 Object . 9
4.2 Aspect . 9
4.3 Systems . 9
4.3.101 Prime systems . 9
4.3.102 Technical systems . 9
4.3.103 Component systems . 9
4.4 Structuring . 9
4.5 Function . 10
4.6 Products and components . 10
4.7 Location . 10
4.8 Types . 10
4.9 Object occurrences and product individuals . 10
4.10 Relations between concepts . 10
5 Structuring principles . 10
5.1 General . 10
5.2 Forming structures . 10
5.3 Function-oriented structure . 10
5.4 Product-oriented structure . 10
5.5 Location-oriented structure . 11
5.6 Type-oriented structure . 11
5.7 Structures based on "other aspects" . 11
5.8 Structures based on more than one aspect . 11
6 Construction of reference designations . 11
6.1 General . 11
6.2 Format of reference designations . 11
6.2.1 Single level . 11
6.2.2 Multi-level . 11
6.2.3 Use of letter codes . 11
6.3 Different structures within the same aspect . 13
7 Reference designation set . 13
8 Designation of locations . 13
8.1 General . 13
8.2 Assemblies . 13
9 Presentation of reference designations . 14
9.1 Reference designations . 14
9.2 Reference designation set . 14
9.3 Presentation of identifiers for the top-node . 14
10 Labelling. 14
11 Presentation of properties for an object . 14
12 Application of the reference designation system . 14
IEC 81346-14:2026 © IEC 2026
Annex A (informative) Information model on the reference designation system . 15
Annex B (informative) Establishment and life cycle of objects . 15
Annex C (informative) Manipulation of objects . 15
Annex D (informative) Interpretation of reference designations using different aspects . 15
Annex E (normative) Object represented with several top nodes in an aspect . 15
Annex F (informative) Examples of multiple structures based on the same aspect . 15
Annex G (normative) Incorporating sub-objects in object structures . 15
Annex H (informative) Example of reference designations within a system . 15
Annex I (normative) Designation of relations between objects . 15
Annex J (normative) Requirements for developing sector-specific parts of the
International Standard 81346 series. 15
Annex K (informative) Metadata resource for structure management . 15
Annex L (informative) Recommendations for documentation of the application of the
reference designation system . 15
Annex M (informative) Fundamental ideas for this document . 16
Annex N (informative) Relationship to other standards . 16
Annex AA (normative) Classification letter codes for systems . 17
AA.1 General . 17
AA.2 Classes of prime systems for manufacturing . 17
AA.3 Classes of technical systems . 18
Annex BB (informative) Example of reference designations within a system. 24
Bibliography . 28

Figure 101 – Relation between prime systems, technical systems and component
systems . 12
Figure 102 – Relation between construction complexes, construction entities and
construction spaces . 13
Figure BB.1 – Process flow diagram for a material handling plant . 24
Figure BB.2 – Overview diagram for part of the material process system (=M1) and
part of the power supply system (=B1) supporting the material processing system . 25
Figure BB.3 – Function-oriented structure tree for parts of the material handling plant . 26
Figure BB.4 – Example of designation of technical systems of a prime system (=M1) in
a block diagram for a chemical plant . 27

Table 101 – Examples of using "?" in a class code . 12
Table 102 – Examples of reference designations . 12
Table AA.1 – Classes of prime systems for manufacturing . 17
Table AA.2 – Classes of technical systems . 18

IEC 81346-14:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Industrial systems, installations and equipment and industrial products -
Structuring principles and reference designations -
Part 14: Manufacturing and processing systems

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
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 81346-14 has been prepared by IEC technical committee 3: Documentation, graphical
symbols and representations of technical information, in close cooperation with ISO technical
committee 10: Technical product documentation. It is an International Standard.
It is published as a double logo standard and has been given the status of a horizontal document
in accordance with the ISO/IEC Directives, Part 1.
The text of this International Standard is based on the following documents:
Draft Report on voting
3/1767/FDIS 3/1776/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
IEC 81346-14:2026 © IEC 2026
The language used for the development of this International Standard is English.
This document is to be read in conjunction with IEC 81346-1:2022. The provisions of the general
rules dealt with in IEC 81346-1:2022 are only applicable to this document insofar as they are
specifically cited. When this document states "addition", "modification" or "replacement", the
relevant text in IEC 81346-1:2022 is to be adapted accordingly.
Subclauses that are numbered with a 101 (102, 103, etc.) suffix are additional to the same
subclause in IEC 81346-1:2022.
Tables, figures, notes and examples in this document that are new are numbered starting
with 101.
New annexes in this document are lettered AA, BB, etc.
A list of parts of the 81346 International Standard, published under the general title Industrial
systems, installations and equipment and industrial products - Structuring principles and
reference designations, can be found on the IEC website.
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.
NOTE In this document, the following print types are used:
• introductory statement in the clauses describing the applicability of the corresponding clause of
IEC 81346-1:2022, in italic type;
• entry system, i.e. manufacturing system and technical system, in the definition of the entry classes, in italic
type;
• name of the parent class in the definition of sub-classes, in italic type;
• in the classification scheme, class codes in bold type.
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, or
– revised.
IEC 81346-14:2026 © IEC 2026
INTRODUCTION
This document considers and supports planning, design, utilization and maintenance of
manufacturing systems. The application of a reference designation system for manufacturing
systems (RDS-MS) can lead to new views and structuring of these activities and thereby offers
opportunities and potential for increasing efficiency and economization.
This document is aligned with the structuring rules provided in IEC 81346-1, and the
classification principles of IEC 81346-2. It also follows the principles for the classification of
prime systems and technical systems provided in ISO 81346-10 and ISO 81346-12.
The focus of this document is to define classes of systems which are used in manufacturing,
and to provide general guidelines for structuring of these systems.
The following advantages of designation systems in accordance with this document and the
81346 International Standard series are:
– the reference designation system can be applied to several technical fields. Mechanical,
electrical and process equipment can be treated the same way – a basis for companywide
synergy effects;
– the reference designation system allows for the integration of any kind of systems and
components without changing the once defined designations;
– the application of different aspects allows, for instance, for the designation of functions
independently from realizing products and their location. The different representation of
systems through multiple aspects and the relations between these allows for a more
inclusive and complete reference model of systems.
The users of this document will be able to manage objects, relations among these and related
properties in a more efficient and consistent way. When implemented, information across
various data processing systems can be handled in an unambiguous way.
Manufacturing is considered as a major part in the five-sector model of the economic sector.
The influence and importance of manufacturing ripples throughout the entire model as
described in the following:
– primary sector (natural sector):
This sector involves the extraction and production of raw materials, for example, farming,
mining, fishing, forestry. The secondary sector relies heavily on this sector for the raw
materials needed to produce products.
EXAMPLE 1 A steel manufacturer needs iron from the mining industry. A tyre manufacturer needs rubber from
the agricultural industry. A car manufacturer needs steel and tyres, thus, implicitly needing iron from the mining
industry and rubber from the agricultural industry.
– secondary sector (industrial sector):
This sector takes the raw materials from the primary sector and transforms them into
finished products. This includes factories producing for example, cars, clothing, electronics,
steel, dairies, breweries. Building and construction is also part of this sector.
– tertiary sector (service sector):
This sector provides services to both individuals and businesses. While manufacturing is
not directly part of this sector, it relies heavily on it.
EXAMPLE 2 Transportation services to move products. Financial services to handle transactions. Marketing
services to sell products.
– quaternary sector (information sector):
This sector deals with information processing and knowledge sharing. It includes IT,
research and development, and consulting. Manufacturing increasingly relies on this sector
for technological advancements, process optimization, and data analysis.
IEC 81346-14:2026 © IEC 2026
– quinary sector (human services sector):
This sector involves services that focus on human development and well-being, such as
education, healthcare, and social work. While not directly involved in production, this sector
contributes to a skilled and healthy workforce, which is essential for a thriving manufacturing
industry.
The different sectors of the five-sector model of the economic sector can be subdivided into
subsectors or industries.
For the primary sector (natural sector), the following subsectors are common:
– biotic sector;
– geological sector.
For the secondary sector (industrial sector), the following subsectors are common:
– construction, partly covered by ISO 81346-12.
– manufacturing sector;
• chemicals;
• electrical and optical;
• heavy industry;
• light industry;
• materials.
– utilities, partly covered by ISO 81346-10.
This document is intended to cover manufacturing systems from the geological aspect of the
primary sector, such as minerals, fossil fuels, and land. It is also intended to cover
manufacturing and construction subsectors from the secondary sector.
The specifications in this document apply for processing, transportation and storage of final
products, as well as for auxiliary systems to support the manufacturing process such as
electrical systems, management systems and waste disposal systems.

IEC 81346-14:2026 © IEC 2026
1 Scope
This part of 81346 International Standard, published jointly by IEC and ISO, provides, in
combination with IEC 81346-1 and IEC 81346-2, rules and recommendations on the structuring
of systems and the information on systems of manufacturing systems. It also provides additional
classification schemes to those of IEC 81346-2 for use in reference designations within
manufacturing systems.
The structuring principles and the classes of objects are intended to provide a clear
identification and localization of the objects, and for use in their labelling in the manufacturing
plant, for their designation in technical documents and for the designation of the technical
documents as well.
The requirements in this document apply for processing, transportation and storage of products,
as well as for systems to support the manufacturing process such as electrical systems,
management systems and waste disposal systems.
This document applies to different areas within the manufacturing industry such as light
industry, electrical and optical industry, chemical industry, material industry and heavy industry.
This document is not applicable for designations related to product individuals (e.g. inventory
number, serial number) nor to the products manufactured.
This document is also a horizontal publication intended for use by technical committees in
preparation of publications related to reference designations in accordance with the principles
laid down in IEC Guide 108.
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 81346-1:2022, Industrial systems, installations and equipment and industrial products -
Structuring principles and reference designations - Part 1: Basic rules
IEC 81346-2:—, Industrial systems, installations and equipment and industrial products -
Structuring principles and reference designations - Part 2: Classification of objects and codes
for classes
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 81346-1:2022,
IEC 81346-2:— 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
___________
Third edition under preparation. Stage at time of publication IEC FDIS 81346-2:2026.
Third edition under preparation. Stage at time of publication IEC FDIS 81346-2:2026.
IEC 81346-14:2026 © IEC 2026
3.1
information
intelligence or knowledge capable of being represented in forms suitable for communication,
storage or processing
Note 1 to entry: Information may be represented for example by signs, symbols, pictures or sounds.
[SOURCE: IEC 60050-701:1988, 701-01-01]
3.2
data
representation of information (3.1) in a formalized manner suitable for human or automatic
processing
Note 1 to entry: Processing includes communication and interpretation.
Note 2 to entry: In English, the word "data" is generally used in plural form. For use in singular form, it can be called
"data item".
[SOURCE: IEC 60050-171:2019, 171-01-02]
3.3
plant
assembly of different systems on a specific site
[SOURCE: ISO 81346-10:2022, 3.10]
3.4
manufacturing
production or processing in defined
quantities
3.5
production
making a single product by a particular
series of actions
3.6
processing
treating matter or information by a
particular series of actions
3.7
equipment
single apparatus or set of devices or apparatuses, or the set of main devices of an installation,
or all devices necessary to perform a specific task
Note 1 to entry: Examples of equipment are a power transformer, the equipment of a substation, measuring
equipment.
[SOURCE: IEC 60050-151:2001, 151-11-25]
3.8
gaseous matter
compressible medium which takes shape of its surrounding container
3.9
liquid matter
incompressible medium which takes shape of its surrounding container
IEC 81346-14:2026 © IEC 2026
3.10
solid matter
incompressible medium which does not take shape of its surrounding container
4 General concepts
4.1 Object
IEC 81346-1:2022, 4.1 applies.
4.2 Aspect
IEC 81346-1:2022, 4.2 applies.
4.3 Systems
IEC 81346-1:2022, 4.3 applies.
Add the following subclauses:
4.3.101 Prime systems
A prime system provides an overall manufacturing step in the manufacturing process or
provides a support for such steps.
A prime system shall be classified in accordance with to the classification scheme in Annex AA,
Table AA.1.
A prime system may incorporate another prime system as one of its constituent system
elements.
4.3.102 Technical systems
A technical system provides a technical solution for a specific step in the manufacturing process
or provides the necessary support for such a technical solution.
A technical system shall be classified in accordance with the scheme defined in Annex AA,
Table AA.2
A technical system may incorporate another technical system recursively as one of its elements.
A technical system shall not incorporate a prime system.
4.3.103 Component systems
Component systems are systems that are well defined with respect to both their inherent
function and implementation.
A component system shall be classified in accordance with IEC 81346-2:—, Table 2.
A component system may incorporate another component system recursively as one of its
elements. A component system shall not incorporate a prime system or a technical system.
NOTE A component system is usually considered as an off-the-shelf product.
4.4 Structuring
IEC 81346-1:2022, 4.4 applies.
IEC 81346-14:2026 © IEC 2026
4.5 Function
IEC 81346-1:2022, 4.5 applies.
4.6 Products and components
IEC 81346-1:2022, 4.6 applies with the following additional note:
NOTE 101 In the context of this document, it is important to note the difference between a product and the product
aspect. A product is the result of the process (work) and is the "thing" that is delivered. The product aspect is a way
to view a system in order to "see" the objects in that system.
4.7 Location
IEC 81346-1:2022, 4.7 applies with the following addition:
Two different aspects shall be applied:
– Host installation aspect: this location aspect shall be applied to relate the location of an
object to locations inside or on a product or product assembly.
EXAMPLE 101 Objects viewed in host of installation are for example locations within or on a cubicle, a console
or a panel.
– Site of installation aspect: this location aspect shall be applied to relate the location of an
object to a location defined inside a larger location irrespective of the existence of physical
objects making up that larger location.
EXAMPLE 102 Objects viewed in the site of installation aspect are a site, a construction entity (a building), a
part of a building, a storey.
4.8 Types
IEC 81346-1:2022, 4.8 applies.
4.9 Object occurrences and product individuals
IEC 81346-1:2022, 4.9 applies.
4.10 Relations between concepts
IEC 81346-1:2022, 4.10 applies.
5 Structuring principles
5.1 General
IEC 81346-1:2022, 5.1 applies.
5.2 Forming structures
IEC 81346-1:2022, 5.2 applies.
5.3 Function-oriented structure
IEC 81346-1:2022, 5.3 applies.
5.4 Product-oriented structure
IEC 81346-1:2022, 5.4 applies.
IEC 81346-14:2026 © IEC 2026
5.5 Location-oriented structure
IEC 81346-1:2022, 5.5 applies.
5.6 Type-oriented structure
IEC 81346-1:2022, 5.6 applies.
5.7 Structures based on "other aspects"
IEC 81346-1:2022, 5.7 applies.
5.8 Structures based on more than one aspect
An identifier of an object should be based on one aspect only. Where multiple aspects are
required, IEC 81346-1:2022, 5.8 applies.
6 Construction of reference designations
6.1 General
IEC 81346-1:2022, 6.1 applies.
6.2 Format of reference designations
6.2.1 Single level
IEC 81346-1:2022, 6.2.1 applies with the following modifications:
Replace Rule 7 with the following:
Rule 7: The prefix signs used to indicate the type of aspect in a reference designation shall be:
a) "=" (EQUALS SIGN) when relating to the function aspect of the object;
b) "‒" (MINUS SIGN) when relating to the product aspect of the object;
c) "+" (PLUS SIGN) when relating to the host installation aspect of the object;
d) "++" (PLUS SIGN, PLUS SIGN) when relating to the site of installation aspect of the object;
e) "%" (PERCENT SIGN) when relating to the type aspect of the object;
f) "#" (NUMBER SIGN) when relating to other aspects of the object.
6.2.2 Multi-level
IEC 81346-1:2022, 6.2.2 applies.
6.2.3 Use of letter codes
IEC 81346-1:2022, 6.2.3 applies with the addition of the following subclauses:
6.2.3.101 Letter codes for the functional aspect and product aspect
Figure 101 illustrates the application of the ONE- TWO- and THREE-letter codes related to
prime systems (ONE), technical systems (TWO) and component systems (THREE).
IEC 81346-14:2026 © IEC 2026
Figure 101 – Relation between prime systems, technical systems
and component systems
For designation of prime systems and technical systems based on their functional aspect,
product aspect or type aspect, the classification schemes in Annex AA shall be applied.
For designation of component systems based on their functional aspect, product aspect or type
aspect, the classification scheme in IEC 81346-2:—, Table 2 shall be applied.
Table 101 shows examples of the use of "?" in a letter code, and Table 102 shows examples of
reference designation in accordance with this document.
Table 101 – Examples of using "?" in a class code
Class code Object Examples
CM? storing object for matters within a stationary closed enclosure powder container system
P? technical system designed to provide prevention or protection equipment and human safety
against unwanted conditions system
K? technical systems designed to adjust flow or an applied quantity velocity and pressure
regulating system
S?? object for detecting a human action and providing an human interaction unit
appropriate response
Table 102 – Examples of reference designations
Object or system Reference designation
Pick and place unit 1 of assembly system 2 =J2=KD1
Main transformer 5 of a welding system 1 of a subassembly system 3 =J3=BB1=TAA5
Electrical cabinet 3 +UCA3
Field sensor 4 of control cabinet 2 of automation system 1 -F1-LC2-BE?4

Annex BB shows an example reference designation within a system based on a functional-
oriented structure of a manufacturing plant, using class codes of this document.
6.2.3.102 Letter codes for the location aspect
Figure 102 illustrates the application of the ONE- TWO- and THREE-letter codes related to
construction complexes (ONE), construction entities (TWO) and construction spaces (THREE).
IEC 81346-14:2026 © IEC 2026
Figure 102 – Relation between construction complexes,
construction entities and construction spaces
For designation of construction complexes based on their location aspect, the classification
schemes in IEC 81346-2:―, Table 3 should be applied.
For designation of construction entities based on their location aspect, the classification
schemes in IEC 81346-2:―, Table 4 should be applied.
For designation of construction spaces based on their location aspect, the classification
schemes in IEC 81346-2:―, Table 5 should be applied.
6.2.3.103 Letter codes for use in the type aspect
For designations based on the type aspect, the classification schemes in IEC 81346-2, the
classification schemes in Annex AA, or any user defined classification schemes may be applied.
The classification scheme used shall be identified in the document where the reference
designation is presented or supporting documentation. The user defined classification scheme
shall be documented in supporting documentation.
6.3 Different structures within the same aspect
IEC 81346-1:2022, 6.3 applies.
7 Reference designation set
IEC 81346-1:2022, Clause 7 applies.
8 Designation of locations
8.1 General
IEC 81346-1:2022, 8.1 applies.
8.2 Assemblies
IEC 81346-1:2022, 8.2 applies.
IEC 81346-14:2026 © IEC 2026
9 Presentation of reference designations
9.1 Reference designations
IEC 81346-1:2022, 9.1 applies.
9.2 Reference designation set
IEC 81346-1:2022, 9.2 applies.
9.3 Presentation of identifiers for the top-node
IEC 81346-1:2022, 9.3 applies.
10 Labelling
IEC 81346-1:2022, Clause 10 applies.
11 Presentation of properties for an object
IEC 81346-1:2022, Clause 11 applies.
12 Application of the reference designation system
IEC 81346-1:2022, Clause 12 applies.
IEC 81346-14:2026 © IEC 2026
Annex A (informative) Information model on the reference designation
system
IEC 81346-1:2022, Annex A applies.
Annex B (informative) Establishment and life cycle of objects
IEC 81346-1:2022, Annex B applies.
Annex C (informative) Manipulation of objects
IEC 81346-1:2022, Annex C applies.
Annex D (informative) Interpretation of reference designations using
different aspects
IEC 81346-1:2022, Annex D applies.
Annex E (normative) Object represented with several top nodes in an
aspect
IEC 81346-1:2022, Annex E applies.
Annex F (informative) Examples of multiple structures based on the same
aspect
IEC 81346-1:2022, Annex F applies.
Annex G (normative) Incorporating sub-objects in object structures
IEC 81346-1:2022, Annex G applies.
Annex H (informative) Example of reference designations within a system
IEC 81346-1:2022, Annex H does not apply.
Annex I (normative) Designation of relations between objects
IEC 81346-1:2022, Annex I applies.
Annex J (normative) Requirements for developing sector-specific parts of
the International Standard 81346 series
IEC 81346-1:2022, Annex J applies.
Annex K (informative) Metadata resource for structure management
IEC 81346-1:2022, Annex K applies.
Annex L (informative) Recommendations for documentation of the
application of the reference designation system
IEC 81346-1:2022, Annex L applies.
IEC 81346-14:2026 © IEC 2026
Annex M (informative) Fundamental ideas for this document
IEC 81346-1:2022, Annex M applies.
Annex N (informative) Relationship to other standards
IEC 81346-1:2022, Annex N applies.
IEC 81346-14:2026 © IEC 2026
Annex AA
(normative)
Classification letter codes for systems
AA.1 General
This annex provides classification schemes for prime systems and technical systems within the
domain of manufacturing systems. The classification schemes are mainly intended to be applied
for designating object occurrences within a function-oriented structure and a product-oriented
structure. They may also be applied for designation of types.
The classification schemes are developed in accordance with the rules and guidelines given in
ISO 704 and ISO 22274.
AA.2 Classes of prime systems for manufacturing
Table AA.1 lists the classe
...