Clarify idleness definition advanced-features-overview.md

Related question:
Azure/azure-sdk-for-net#18591 (comment)

Author: gukoff

articles/service-bus-messaging/advanced-features-overview.md

@@ -33,7 +33,7 @@ A queue or subscription client can defer retrieval of a received message until a
 A transaction groups two or more operations together into an execution scope. Service Bus allows you to group operations against multiple messaging entities within the scope of a single transaction. A message entity can be a queue, topic, or subscription. For more information, see [Overview of Service Bus transaction processing](service-bus-transactions.md).
 
 ## Autodelete on idle
-Autodelete on idle enables you to specify an idle interval after which a queue or topic subscription is automatically deleted. The interval is reset when there is traffic on the entity. The minimum duration is 5 minutes. 
+Autodelete on idle enables you to specify an idle interval after which a queue or topic subscription is automatically deleted. The interval is reset when a message is added to or removed from the subscription. The minimum duration is 5 minutes. 
 
 ## Duplicate detection
 The duplicate detection feature enables the sender to resend the same message again and for the broker to drop a potential duplicate. For more information, see [Duplicate detection](duplicate-detection.md).
@@ -47,7 +47,8 @@ When an Azure region experiences downtime, the disaster recovery feature enables
 ## Security
 Service Bus supports standard [AMQP 1.0](service-bus-amqp-overview.md) and [HTTP or REST](/rest/api/servicebus/) protocols and their respective security facilities, including transport-level security (TLS). Clients can be authorized for access using [Shared Access Signature](service-bus-sas.md) or [Azure Active Directory](service-bus-authentication-and-authorization.md) role-based security. 
 
-For protection against unwanted traffic, Service Bus provides [security features](network-security.md) such as IP firewall and integration with virtual networks. 
+For protection against unwanted 
+ic, Service Bus provides [security features](network-security.md) such as IP firewall and integration with virtual networks. 
 
 ## Next steps
 See [Service Bus messaging samples](service-bus-samples.md) that show how to use these Service Bus features.