A documentation section has been added to the admin panel.

app/application/lang/en/validation.php

@@ -151,6 +151,8 @@ return [
     'no_type'              => 'The :attribute can only use: :type.',
     'captcha'              => 'Failed to pass human verification.',
     'http_host'            => 'The :attribute must be a valid domain.',
+    'parent'               => 'A parent cannot refer to itself.',
+    'parent_cycle_detected' => 'Category ID occurs in the parent chain.',
     'attributes'           => [
         'address'                  => 'address',
         'affiliate_url'            => 'affiliate URL',
@@ -301,5 +303,9 @@ return [
         'translations'             => 'translations',
         'translations.*.code'      => 'translations code',
         'translations.*.text'      => 'translations',
+        'parent_id'                => 'parent',
+        'content.*.title'          => 'title',
+        'content.*.content'        => 'content',
+        'category_id'              => 'category',
     ],
 ];