diff --git a/CHANGELOG.md b/CHANGELOG.md
index 09d48bbf0a5..e856b9e1da1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,6 +27,8 @@ release.
   ([#4534](https://github.com/open-telemetry/opentelemetry-specification/pull/4534))
 - Stabilize SDK and No-Op `Logger.Enabled`.
   ([#4536](https://github.com/open-telemetry/opentelemetry-specification/pull/4536))
+- `SeverityNumber=0` MAY be used to represent an unspecified value.
+  ([#4535](https://github.com/open-telemetry/opentelemetry-specification/pull/4535))
 
 ### Baggage
 
diff --git a/specification/logs/data-model.md b/specification/logs/data-model.md
index 72bdb55c7f1..ec17ba4c0ab 100644
--- a/specification/logs/data-model.md
+++ b/specification/logs/data-model.md
@@ -303,6 +303,8 @@ events. Larger numerical values in each range represent more important (more
 severe) events. For example `SeverityNumber=17` describes an error that is less
 critical than an error with `SeverityNumber=20`.
 
+`SeverityNumber=0` MAY be used to represent an unspecified value.
+
 #### Mapping of `SeverityNumber`
 
 Mappings from existing logging systems and formats (or **source format** for