From 5d11632068d1820d7d06a9f25e57d9fd35707e46 Mon Sep 17 00:00:00 2001 From: Emmanuel Mathot Date: Mon, 17 Nov 2025 22:10:19 +0100 Subject: [PATCH] docs: clarify unit field usage in common metadata --- commons/common-metadata.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/commons/common-metadata.md b/commons/common-metadata.md index 77acf98e..f398fed9 100644 --- a/commons/common-metadata.md +++ b/commons/common-metadata.md @@ -288,6 +288,10 @@ It is STRONGLY RECOMMENDED to provide units in one of the following two formats: - [UCUM](https://ucum.org/): The unit code that is compliant to the UCUM specification. - [UDUNITS-2](https://ncics.org/portfolio/other-resources/udunits2/): The unit symbol if available, otherwise the singular unit name. +To specify that a value is unitless (dimensionless), provide an empty string (`""`). +If unit information is not available or not applicable, the `unit` field SHOULD be omitted entirely. +The value `null` is not valid for this field. + ### Statistics Object Statistics usually specify the range of values by providing the `minimum` and `maximum` values,