Allow implementations to export log records with duplicate keys in a map as opt-in

CHANGELOG.md

@@ -26,6 +26,8 @@ release.
   ([#3898](https://github.com/open-telemetry/opentelemetry-specification/pull/3898))
 - Fix what can be modified via `ReadWriteLogRecord`.
   ([#3907](https://github.com/open-telemetry/opentelemetry-specification/pull/3907))
+- Allow SDKs to have duplicated keys in a map if they provide means to have them deduplicated when log records are exported.
+  ([#3938](https://github.com/open-telemetry/opentelemetry-specification/pull/3938))
 
 ### Events
 

specification/logs/data-model.md

@@ -120,7 +120,9 @@ Value of type `any` can be one of the following:
 
 Value of type `map<string, any>` is a map of string keys to `any` values. The
 keys in the map are unique (duplicate keys are not allowed). The representation
-of the map is language-dependent.
+of the map is language-dependent. The SDKs MAY allow duplicated keys (represent
+the map as an array/list of key-values) as long as they provide means to have
+them deduplicated when log records are exported.
 
 Arbitrary deep nesting of values for arrays and maps is allowed (essentially
 allows to represent an equivalent of a JSON object).