International Standards and Conformity Assessment for all electrical, electronic and related technologies
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Drafting IEC publications



26 Footnotes

26.1 Purpose or rationale

Footnotes to the text of a document are used to give additional contextual information to a specific item in the text. The document shall be usable without the footnotes.

For rules on footnotes to figures, see 28.5.5.


For rules on footnotes to tables, see 29.5.2 .


26.2 Title

Footnotes do not have a title.


26.3 Numbering and subdivision

Footnotes shall be numbered sequentially throughout the document. Normally, footnote references are indicated using Arabic numerals. Exceptionally, other systems (a, b, c, etc.; *, **, ***, etc.; †, ‡, etc.) can be used, for example when there is the possibility of confusing them with superscript numbers.


26.4 Referencing

Footnotes shall be referenced in the text.


Use, for example, the following form for references to footnotes:

  • ISO 1234:–1 lists the test methods for…


1  Under preparation. Stage at the time of publication: ISO/DIS 1234:2014.



26.5 Specific principles and rules

A footnote can appear anywhere within the text of a document apart from terminological entries.


Footnotes shall not contain requirements (e.g. use of "shall", see Table 3) or any information considered indispensable for the use of the document, for example instructions (imperative mood), recommendations (e.g. use of "should", see Table 4) or permission (e.g. use of "may", see Table 5). Footnotes should be written as a statement of fact.


26.6 Examples




C.1.1 Introduction

...multiplex real-time PCR method based on TaqMan®7.


7   TaqMan® is a trademark of Roche Molecular Systems. This information is given for the convenience of users of this document and does not constitute an endorsement by ISO of the product named.



…such effects of salt mist on connectors has been demonstrated [2] 5.
5    Numbers in square brackets refer to the Bibliography.