diff --git a/OneM2M_Types.ttcn b/OneM2M_Types.ttcn
index 8b03484d29ad411b105602c0a81e41ad8d84dc14..18e8ac57d9f1ca2ec1152e08233444bc9052114a 100644
--- a/OneM2M_Types.ttcn
+++ b/OneM2M_Types.ttcn
@@ -2066,9 +2066,9 @@ type record EventNotificationCriteria
 	Timestamp expireAfter optional,
 	XSD.NonNegativeInteger sizeAbove optional,
 	XSD.PositiveInteger sizeBelow optional,
-	record of OperationMonitor operationMonitor_list,
+	record of OperationMonitor operationMonitor_list optional,//It should be optional
 	AttributeList_1 attribute optional,
-	record length(0 .. 6) of NotificationEventType notificationEventType_list,
+	record length(0 .. 6) of NotificationEventType notificationEventType_list optional,//It should be optional
 	record length(1 .. infinity) of ResourceType childResourceType optional,
 	MissingData missingData optional,
 	FilterOperation filterOperation optional
@@ -2366,13 +2366,13 @@ type record AccessControlRule
 			record length(1 .. infinity) of Ipv6 ipv6Addresses optional
 		} accessControlIpAddresses optional,
 		LocationRegion accessControlLocationRegion optional
-	} accessControlContexts_list,
+	} accessControlContexts_list optional,
 	XSD.Boolean accessControlAuthenticationFlag optional,
 	record of record {
 		ResourceType resourceType optional,
 		SpecializationType specializationID optional,
 		record length(1 .. infinity) of ResourceType childResourceType
-	} accessControlObjectDetails_list
+	} accessControlObjectDetails_list optional
 }
 with {
   variant "name as uncapitalized";
@@ -7062,7 +7062,7 @@ with {
 
 type record ListOfChildResourceRef
 {
-	record length(1 .. infinity) of ChildResourceRef resourceRef_list
+	record length(0 .. infinity) of ChildResourceRef resourceRef_list
 }
 with {
   variant "name as uncapitalized";