diff --git a/staging/src/k8s.io/apiserver/pkg/server/options/admission.go b/staging/src/k8s.io/apiserver/pkg/server/options/admission.go
index b6abf70c46b..a870f01afe2 100644
--- a/staging/src/k8s.io/apiserver/pkg/server/options/admission.go
+++ b/staging/src/k8s.io/apiserver/pkg/server/options/admission.go
@@ -67,7 +67,11 @@ func NewAdmissionOptions() *AdmissionOptions {
 // AddFlags adds flags related to admission for a specific APIServer to the specified FlagSet
 func (a *AdmissionOptions) AddFlags(fs *pflag.FlagSet) {
 	fs.StringSliceVar(&a.PluginNames, "admission-control", a.PluginNames, ""+
-		"Ordered list of plug-ins to do admission control of resources into cluster. "+
+		"Admission is divided into two phases. "+
+		"In the first phase, only mutating admission plugins run. "+
+		"In the second phase, only validating admission plugins run. "+
+		"The names in the below list may represent a validating plugin, a mutating plugin, or both. "+
+		"Within each phase, the plugins will run in the order in which they are passed to this flag. "+
 		"Comma-delimited list of: "+strings.Join(a.Plugins.Registered(), ", ")+".")
 
 	fs.StringVar(&a.ConfigFile, "admission-control-config-file", a.ConfigFile,