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Drafting IEC publications



10 Referencing

10.1 Purpose or rationale

The entire collection of International Standards published by ISO and IEC is interrelated and forms a system whose integrity has to be preserved.

Therefore, references to particular pieces of text should be used instead of repetition of the original source material. Repetition introduces the risk of error or inconsistency and increases the length of the document. However, if it is considered necessary to repeat such material, its source shall be referenced precisely.

Imprecise references such as "the following clause" or "the figure above" shall not be used.


References can be made

  • to other parts of the document, e.g. a clause, table or figure (see 10.6), or
  • to other documents or publications (see 10.2).

References can be

  • informative (see Clause 21), or
  • normative (see Clause 15).

References can be

  • dated (see 10.5), or
  • undated (see 10.4).


It is often useful to copy relevant terminological entries into the Terms and definitions clause, in which case the source is cited:


item, thing or entity that has potential or actual value to an organization

[SOURCE: ISO 55500:2014, 3.2.1]



Material copied from an external document:



1 Life; maintenance time.


SOURCE: DISSADO, L.A., FOTHERGILL, J.C (1992)[5], reproduced with the permission of the authors


Figure A.6 – Property versus time behaviour, detection of threshold
(end point,
PL) and maintenance time


For management system standards, the rules of the ISO/IEC Directives, Part 1, Consolidated ISO Supplement apply.


10.2 Permitted referenced documents

Normatively referenced documents shall be documents published by ISO or IEC. In the absence of appropriate ISO or IEC documents, those published by other bodies may be listed as normative references provided that

a) the referenced document is recognized by the committee as having wide acceptance and authoritative status,


b) the committee has the agreement of the authors or publishers (where known) of the referenced document for its inclusion as a reference,


c) the authors or publishers (where known) have also agreed to inform the committee of their intention to revise the referenced document and what points the revision will affect,


d) the document is available under commercial terms which are fair, reasonable and non-discriminatory, and


e) any patented item required for the implementation of the document is available to be licensed in accordance with the ISO/IEC Directives, Part 1, 2021, 2.14, "Reference to patented items".

Informative reference may be made to any other type of document. Informative references shall be listed in the Bibliography.

ISO and IEC normatively referenced documents shall have reached at least the enquiry stage (40.20 DIS or CDV).

The committees shall validate all referenced documents when a document is revised.


The normative references list shall not include the following:

  • referenced documents which are not publicly available (in this context, "publicly available" means published documents which are available free of charge, or available commercially under fair, reasonable and non-discriminatory terms to any user);
  • referenced documents which are cited only informatively as bibliographic or background material.

10.3 Presentation of references

Documents shall be referred to by their number, and if applicable, date of publication and title.




ISO/TR 12353-3:2013, Road vehicles – Traffic accident analysis – Part 3: Guidelines for the interpretation of recorded crash pulse data to determine impact severity
ISO 14044:2006, Environmental management – Life cycle assessment – Requirements and guidelines
ISO 17101-2:2012, Agricultural machinery – Thrown-object test and acceptance criteria – Part 2: Flail mowers
ISO 14617 (all parts), Graphical symbols for diagrams
ISO/IEC 17025:2005, General requirements for the competence of testing and calibration laboratories
IEC 61175, Industrial systems, installations and equipment and industrial products – Designation of signals – Basic rules


For other referenced documents and information resources (printed, electronic or otherwise), the relevant rules set out in ISO 690 shall be followed.




Printed book or monograph:
GREAT BRITAIN. Data Protection Act 1984. Schedule 1, c35, Part 1, Clause 7. London: HMSO


Electronic book or monograph:
INTERNET ENGINEERING TASK FORCE (IETF). RFC 3979: Intellectual Property Rights in IETF Technology [online]. Edited by S. Bradner. March 2005 [viewed 2020-09-09]. Available at https://www.ietf.org/rfc/rfc3979.txt


Contribution to printed serial publication:
AMAJOR, L.C. The Cenomanian hiatus in the Southern Benue Trough, Nigeria. Geological Magazine. 1985, 122(1), 39-50. ISSN 0016-7568


Contribution to online serial publication:
STRINGER, John A., et al. Reduction of RF-induced sample heating with a scroll coil resonator structure for solid-state NMR probes. Journal of Magnetic Resonance [online]. Elsevier. March 2005, 173(1), 40-48 [viewed 2018-04-17]. Available at: http://dx.doi.org/10.1016/j.jmr.2004.11.015


For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably, the primary source of the referenced document should be cited, in order to ensure traceability.

The information shall include the method of access to the referenced document and the full network address, with the same punctuation and use of uppercase and lowercase letters as given in the source (see ISO 690).


Furthermore, the referenced document should be expected to remain valid for the expected life of the referring document.




ISO/IEC Directives, IEC Supplement. International Electrotechnical Commission. Available at https://www.iec.ch/members_experts/refdocs/


Statutes and directives. International Electrotechnical Commission, ©2004-2010 [viewed 2021-02-09]. Available at https://www.iec.ch/members_experts/refdocs/


ISO 7000/IEC 60417 [online database], Graphical symbols for use on equipment [viewed 2021-04-18]. Available at https://www.graphical-symbols.info/


To simplify cross-referencing to the Bibliography, entries may be numbered and cross-references made to the number of the corresponding entry. See 21.4.




The complete data set is provided in Reference [6].



10.4 Undated references

Undated references may be made:

  • only to a complete document;
  • if it will be possible to use all future changes of the referenced document for the purposes of the referring document;
  • when it is understood that the reference will include all amendments to and revisions of the referenced document.

The date of publication or dash (see 10.5 ) shall not be given for undated references. When an undated reference is to all parts of a series:


  • the standard identifier shall be followed by "(all parts)" in the lists of documents in the Normative references clause and in the Bibliography;
  • the form "the ISO xxxx series" or "the IEC xxxx series" shall be used in the text.


In the Normative references clause or Bibliography, use the following forms to list undated references.




IEC 60335 (all parts), Household and similar electrical appliances – Safety
IEC 60335-1, Household and similar electrical appliances – Safety – Part 1: General requirements

Reference to all parts
Reference to a single part


In the text, use the following forms to make undated references to a document or series.



  • “ … use the methods specified in ISO 128-20 and ISO 80000-1 … ”;
  • “ … IEC 60417 shall be used… ”.
  • “ "… use the test methods of the IEC 60335 series …"


10.5 Dated references

Dated references are references to

  • a specific edition, indicated by the date of publication or
  • a specific enquiry or final draft, indicated by a dash.

Normative references to enquiry or final drafts are potentially risky, and are strongly discouraged, as the referenced document can change before publication.
For dated references, each shall be given with its year of publication. In the case of enquiry or final drafts, the date shall be replaced with a dash together with an explanatory footnote (see Example 2).

The date of publication shall be indicated by the year or, for documents for which more than one edition of the document or an element within the document will be published in the same calendar year, the year of publication and the month (and, where necessary, the day).

If the referenced document is amended or revised, the dated references to it shall be reviewed to assess whether they shall be updated or not.

In this context, a part is regarded as a separate document.

Within the text, references to specific elements (e.g. clauses or subclauses, tables and figures) of a referenced document shall always be dated, because these elements are sometimes renumbered in subsequent editions of the referenced document.


In the Normative references clause or the Bibliography, use the following forms to list dated references.




IEC 62271-1:2007, High-voltage switchgear and controlgear – Part 1: Common specifications

Dated reference to a standard

IEC 62271-1:2007/AMD1:2011, High-voltage switchgear and controlgear – Part 1: Common specifications

Dated reference to an amendment (using IEC conventions)

ISO 7131:2009/Amd 1:2017, Earth-moving machinery – Loaders – Terminology and commercial specifications – Amendment 1

Dated reference to an amendment (using ISO conventions)


In the text, use the standard identifier rather than the title when referring to an ISO or IEC document. The titles are usually only written out in full in the Normative references clause and in the Bibliography.


In the text, use the following forms to make dated references to a document.



… as specified in IEC 64321-4:1996, Table 1, …

Dated reference to a specific table in another published document

… … perform the tests given in IEC 60068-1:201…

Dated reference to a published document

… use symbol IEC 60417-5017:2006-08 …

Dated reference to an entry within a database standard

… in accordance with IEC 62271-1:2007/AMD1:2011 …

Dated reference to an amendment (using IEC conventions)

… in accordance with IEC 62271-1:2007 and IEC 62271-1:2007/AMD1:2011 …

Dated reference to a published document and its amendment (using IEC conventions)

… ISO 1234:–2, lists the test methods for…
2    Under preparation. Stage at the time of publication: ISO/DIS 1234:2014.

Dated reference to an enquiry or final draft (typically, the footnote is inserted the first time the reference appears.)



Dated versus undated references:


The test methods of IEC 61300-2-2 shall be used.

This is a reference to a complete document and it can therefore be undated

The dimensions shall be in accordance with IEC 60793-2-50:2018, Table B.1.

This is a reference to a specific element in the referenced document and it is therefore dated


10.6 References in a document to itself

For an individual document, the form "this document" shall be used.


In contexts where it is necessary to specify the number of the document, it is acceptable to do so.



This document outlines test methodologies used for salt mist conditions.

The ISO 3166 Maintenance Agency facilitates the work of experts by providing them with information on …



References to particular elements of the text (e.g. clauses, subclauses, tables, figures, mathematical formulae, annexes) are made by using their number.




Annex B outlines test methodologies used for salt mist conditions.



References shall not be made to page numbers, since pagination can change if the referenced document is published in different formats, or if the document is revised.

If content has been subdivided into a series of parts, reference in the text to the entire series including the individual document shall be made using the form "the ISO xxxx series" or "the IEC xxxx series".




The formulae in the ISO 10300 series are intended to establish uniformly acceptable methods for calculating the pitting resistance and bending strength of …



Such undated references are understood to include all amendments and revisions to the referenced document.