Merge pull request #269194 from roygara/zoneUpdate

Clarifying explanation

Author: prmerger-automator[bot]

articles/reliability/availability-zones-overview.md

@@ -41,7 +41,7 @@ For information on service-specific reliability support using availability zones
 
 ## Physical and logical availability zones
 
-Each datacenter is assigned to a physical zone. Physical zones are mapped to logical zones in your Azure subscription, and different subscriptions might have a different mapping order. Azure subscriptions are automatically assigned their mapping at the time the subscription is created.
+Each datacenter is assigned to a physical zone. Physical zones are mapped to logical zones in your Azure subscription, and different subscriptions might have a different mapping order. Azure subscriptions are automatically assigned their mapping at the time the subscription is created. Because of this, the zone mapping for one subscription could be different for other subscriptions. For example: Subscription A may have physical zone X mapped to logical zone 1, while subscription B has physical zone X mapped to logical zone 3, instead.
 
 To understand the mapping between logical and physical zones for your subscription, use the [List Locations Azure Resource Manager API](/rest/api/resources/subscriptions/list-locations). You can use the [Azure CLI](/cli/azure/install-azure-cli) or [Azure PowerShell](/powershell/azure/what-is-azure-powershell) to retrieve the information from the API.