Clairly Resourcequota limit for PriorityClass

Signed-off-by: Weiping Cai <[email protected]>

content/en/docs/concepts/policy/resource-quotas.md

@@ -610,17 +610,29 @@ plugins:
         values: ["cluster-services"]
 ```
 
-Now, "cluster-services" pods will be allowed in only those namespaces where a quota object with a matching `scopeSelector` is present.
-For example:
+Then, create a corresponding resource quota object in `kube-system` namespace:
 
-```yaml
+```shell
+$ cat ./quota.yml
+- apiVersion: v1
+  kind: ResourceQuota
+  metadata:
+    name: pods-cluster-services
+  spec:
     scopeSelector:
       matchExpressions:
-      - scopeName: PriorityClass
-        operator: In
+      - operator : In
+        scopeName: PriorityClass
         values: ["cluster-services"]
+$ kubectl create -f ./quota.yml -n kube-system`
 ```
 
+In this case, a pod creation will be allowed if:
+1. Pod has no priority class and created in any namespace.
+2. Pod has priority class other than `cluster-services` and created in any namespace.
+3. Pod has priority class `cluster-services` and created in `kube-system` namespace, and passed resource quota check.
+Pod creation will be rejected if pod has priority class `cluster-services` and created in namespace other than `kube-system`
+
 ## {{% heading "whatsnext" %}}
 
 - See [ResourceQuota design doc](https://git.k8s.io/community/contributors/design-proposals/resource-management/admission_control_resource_quota.md) for more information.