diff --git a/v3_18_0/CDT-enumerationTypes-v3_18_0.xsd b/v3_18_0/CDT-enumerationTypes-v3_18_0.xsd
index 8b0fb5df32f170371f135ed7b7da028487c71d78..904161962228519de4626a6093f2f5af9f498260 100644
--- a/v3_18_0/CDT-enumerationTypes-v3_18_0.xsd
+++ b/v3_18_0/CDT-enumerationTypes-v3_18_0.xsd
@@ -1380,29 +1380,6 @@ oneM2M EXPRESSLY ADVISES ANY AND ALL USE OF OR RELIANCE UPON THIS INFORMATION PR
 		</xs:restriction>
 	</xs:simpleType>
 	
-	
-	<xs:simpleType name="serializationType">
-		<xs:annotation>
-			<xs:documentation>Used for the triggerInfoSrializationType field of trigger requests on Mcn</xs:documentation>
-		</xs:annotation>
-		<xs:restriction base="xs:integer">
-			<!-- XML -->
-			<xs:enumeration value="1" />
-			<!-- JSON -->
-			<xs:enumeration value="2" />
-			<!-- XML + JSON -->
-			<xs:enumeration value="3" />
-			<!-- CBOR -->
-			<xs:enumeration value="4" />
-			<!-- XML + CBOR -->
-			<xs:enumeration value="5" />
-			<!-- JSON + CBOR -->
-			<xs:enumeration value="6" />
-			<!-- XML + JSON + CBOR -->
-			<xs:enumeration value="7" />
-		</xs:restriction>
-	</xs:simpleType>
-	
 	<xs:simpleType name="authorizationDecision">
 		<xs:annotation>
 			<xs:documentation>Used for the decision attribute of the of authorizationDecision resource</xs:documentation>