Adding documentation for cascading deletion of federated resources

docs/user-guide/federation/index.md

@@ -46,3 +46,26 @@ The following guides explain some of the resources in detail:
 
 [API reference docs](/federation/docs/api-reference/readme/) lists all the
 resources supported by federation apiserver.
+
+## Cascading deletion
+
+Kubernetes version 1.5 includes support for cascading deletion of federated
+resources. With cascading deletion, when you delete a resource from the
+federation control plane, the corresponding resources in all underlying clusters
+are also deleted.
+
+To enable cascading deletion, set the option
+`DeleteOptions.orphanDependents=false` when you delete a resource from the
+federation control plane.
+
+The following Federated resources are affected by cascading deletion:
+
+* Ingress
+* Namespace
+* ReplicaSet
+* Secret
+* Deployment
+* DaemonSet
+
+Note: By default, deleting a resource from federation control plane does not
+delete the corresponding resources from underlying clusters.