Apologies, it's a note, not a footnote. But notes in ISO standards aren't normative either. This is a general principle of ISO standards, see https://share.ans

Apologies, it's a note, not a footnote. But notes in ISO standards aren't normative either. This is a general principle of ISO standards, see https://share.ansi.org/Shared%20Documents/Standards%20Activities/International%20Standardization/ISO/ISO_IEC_Directives_Part_2.pdf https://share.ansi.org/Shared%20Documents/Standards%20Activi...: > 6.5 Other informative elements > 6.5.1 Notes and examples integrated in the text > Notes and examples integrated in the text of a document shall only be used for giving additional information intended to assist the understanding or use of the document. They shall not contain requirements ("shall"; see 3.3.1 and Table H.1) or any information considered indispensable for the use of the document, e.g. instructions (imperative; see Table H.1), recommendations ("should"; see 3.3.2 and Table H.2) or permission ("may"; see Table H.3). Notes may be written as a statement of fact.