New instance annotation @Core.changed for delta messages

vocabularies/Org.OData.Core.V1.json

@@ -703,6 +703,13 @@
                 "$Nullable": true,
                 "@Core.Description": "Commonly used identifer for a Feature"
             }
+        },
+        "changed": {
+            "$Kind": "Term",
+            "$Type": "Edm.Boolean",
+            "$Nullable": true,
+            "@Core.Description": "Instance annotation on [added/changed entities in a delta message](https://docs.oasis-open.org/odata/odata-json-format/v4.01/odata-json-format-v4.01.html#sec_AddedChangedEntity), `true` indicating that the entity existed and was changed when the delta message was produced",
+            "@Core.LongDescription": "The presence or absence of `@Core.changed` does not alter the idempotent nature of a delta message, nor does it alter the UPSERT nature of an added/changed entity.\n\nThe recipient of a delta message MAY use the `@Core.changed` annotation for optimization only, ultimately any received added/changed entity MUST be processed as an UPSERT.\n\nThe `@Core.changed` annotation expresses the sender's local knowledge when generating the delta message, and this local sender knowledge can be out of date by the time the recipient processes the delta message for a variety of reasons, for example if the same delta message is processed again, or a preceding delta message was lost, or delta messages are processed in a sequence different from their creation sequence."
         }
     }
 }

vocabularies/Org.OData.Core.V1.md

@@ -48,6 +48,7 @@ Term|Type|Description
 [OperationAvailable](./Org.OData.Core.V1.xml#L507:~:text=<Term%20Name="-,OperationAvailable,-")|Boolean?|<a name="OperationAvailable"></a>Action or function is available<br>The annotation value will usually be an expression, e.g. using properties of the binding parameter type for instance-dependent availability, or using properties of a singleton for global availability. The static value `null` means that availability cannot be determined upfront and is instead expressed as an operation advertisement.
 [SymbolicName](./Org.OData.Core.V1.xml#L518:~:text=<Term%20Name="-,SymbolicName,-")|[SimpleIdentifier](#SimpleIdentifier)|<a name="SymbolicName"></a>A symbolic name for a model element
 [GeometryFeature](./Org.OData.Core.V1.xml#L526:~:text=<Term%20Name="-,GeometryFeature,-")|[GeometryFeatureType?](#GeometryFeatureType)|<a name="GeometryFeature"></a>A [Feature Object](https://datatracker.ietf.org/doc/html/rfc7946#section-3.2) represents a spatially bounded thing
+[changed](./Org.OData.Core.V1.xml#L542:~:text=<Term%20Name="-,changed,-")|Boolean?|<a name="changed"></a>Instance annotation on [added/changed entities in a delta message](https://docs.oasis-open.org/odata/odata-json-format/v4.01/odata-json-format-v4.01.html#sec_AddedChangedEntity), `true` indicating that the entity existed and was changed when the delta message was produced<br>The presence or absence of `@Core.changed` does not alter the idempotent nature of a delta message, nor does it alter the UPSERT nature of an added/changed entity.<br/>The recipient of a delta message MAY use the `@Core.changed` annotation for optimization only, ultimately any received added/changed entity MUST be processed as an UPSERT.<br/>The `@Core.changed` annotation expresses the sender's local knowledge when generating the delta message, and this local sender knowledge can be out of date by the time the recipient processes the delta message for a variety of reasons, for example if the same delta message is processed again, or a preceding delta message was lost, or delta messages are processed in a sequence different from their creation sequence.
 
 ## <a name="RevisionType"></a>[RevisionType](./Org.OData.Core.V1.xml#L80:~:text=<ComplexType%20Name="-,RevisionType,-")
 

vocabularies/Org.OData.Core.V1.xml

@@ -539,6 +539,17 @@ Any simple identifier | Any type listed in `Validation.OpenPropertyTypeConstrain
         </Property>
       </ComplexType>
 
+      <Term Name="changed" Type="Edm.Boolean" Nullable="true">
+        <Annotation Term="Core.Description" String="Instance annotation on [added/changed entities in a delta message](https://docs.oasis-open.org/odata/odata-json-format/v4.01/odata-json-format-v4.01.html#sec_AddedChangedEntity), `true` indicating that the entity existed and was changed when the delta message was produced" />
+        <Annotation Term="Core.LongDescription">
+          <String>The presence or absence of `@Core.changed` does not alter the idempotent nature of a delta message, nor does it alter the UPSERT nature of an added/changed entity.
+
+The recipient of a delta message MAY use the `@Core.changed` annotation for optimization only, ultimately any received added/changed entity MUST be processed as an UPSERT.
+
+The `@Core.changed` annotation expresses the sender's local knowledge when generating the delta message, and this local sender knowledge can be out of date by the time the recipient processes the delta message for a variety of reasons, for example if the same delta message is processed again, or a preceding delta message was lost, or delta messages are processed in a sequence different from their creation sequence.</String>
+        </Annotation>
+      </Term>
+
     </Schema>
   </edmx:DataServices>
 </edmx:Edmx>