diff --git a/docs/guide/authorization.md b/docs/guide/authorization.md
index 093305c..e0a59d9 100644
--- a/docs/guide/authorization.md
+++ b/docs/guide/authorization.md
@@ -130,6 +130,8 @@ use yii\rbac\Rule;
 
 class NotGuestRule extends Rule
 {
+    public $name = 'notGuestRule';
+
     public function execute($params, $data)
     {
         return !Yii::$app->user->isGuest;
@@ -152,17 +154,17 @@ return [
     ],
     'items' => [
         // HERE ARE YOUR MANAGEMENT TASKS
-        'manageThing0' => ['type' => Item::TYPE_OPERATION, 'description' => '...', 'ruleName' => NULL, 'data' => NULL],
-        'manageThing1' => ['type' => Item::TYPE_OPERATION, 'description' => '...', 'ruleName' => NULL, 'data' => NULL],
-        'manageThing2' => ['type' => Item::TYPE_OPERATION, 'description' => '...', 'ruleName' => NULL, 'data' => NULL],
-        'manageThing3' => ['type' => Item::TYPE_OPERATION, 'description' => '...', 'ruleName' => NULL, 'data' => NULL],
+        'manageThing0' => ['type' => Item::TYPE_OPERATION, 'description' => '...', 'ruleName' => null, 'data' => null],
+        'manageThing1' => ['type' => Item::TYPE_OPERATION, 'description' => '...', 'ruleName' => null, 'data' => null],
+        'manageThing2' => ['type' => Item::TYPE_OPERATION, 'description' => '...', 'ruleName' => null, 'data' => null],
+        'manageThing3' => ['type' => Item::TYPE_OPERATION, 'description' => '...', 'ruleName' => null, 'data' => null],
 
         // AND THE ROLES
         'guest' => [
             'type' => Item::TYPE_ROLE,
             'description' => 'Guest',
-            'ruleName' => NULL,
-            'data' => NULL
+            'ruleName' => null,
+            'data' => null
         ],
 
         'user' => [
@@ -173,7 +175,7 @@ return [
                 'manageThing0', // User can edit thing0
             ],
             'ruleName' => $notGuest->name,
-            'data' => NULL
+            'data' => null
         ],
 
         'moderator' => [
@@ -183,8 +185,8 @@ return [
                 'user',         // Can manage all that user can
                 'manageThing1', // and also thing1
             ],
-            'ruleName' => NULL,
-            'data' => NULL
+            'ruleName' => null,
+            'data' => null
         ],
 
         'admin' => [
@@ -194,8 +196,8 @@ return [
                 'moderator',    // can do all the stuff that moderator can
                 'manageThing2', // and also manage thing2
             ],
-            'ruleName' => NULL,
-            'data' => NULL
+            'ruleName' => null,
+            'data' => null
         ],
 
         'godmode' => [
@@ -205,8 +207,8 @@ return [
                 'admin',        // can do all that admin can
                 'manageThing3', // and also thing3
             ],
-            'ruleName' => NULL,
-            'data' => NULL
+            'ruleName' => null,
+            'data' => null
         ],
     ],
 ];