diff --git a/lib/flagutil/array.go b/lib/flagutil/array.go
index 231cf41c1..ebd81a20b 100644
--- a/lib/flagutil/array.go
+++ b/lib/flagutil/array.go
@@ -10,6 +10,8 @@ import (
 // NewArray returns new Array with the given name and description.
 func NewArray(name, description string) *Array {
 	var a Array
+	description += "\nSupports `array` of values separated by comma" +
+		" or specified via multiple flags."
 	flag.Var(&a, name, description)
 	return &a
 }