diff --git a/aliyun-oss-wordpress.php b/aliyun-oss-wordpress.php
index 25106aa..9073338 100644
--- a/aliyun-oss-wordpress.php
+++ b/aliyun-oss-wordpress.php
@@ -575,6 +575,11 @@ function oss_setting_post_thumbnail_style($html, $post_id, $post_image_id)
     return $html;
 }
 
+/**
+ * @link https://help.aliyun.com/zh/oss/user-guide/regions-and-endpoints
+ * @param string $regional
+ * @return void
+ */
 function oss_get_regional($regional)
 {
     $options = [
diff --git a/readme.txt b/readme.txt
index 02d862d..0f3a77a 100644
--- a/readme.txt
+++ b/readme.txt
@@ -76,7 +76,7 @@ License URI: http://www.apache.org/licenses/LICENSE-2.0.html
 
 == Changelog ==
 
-= 1.4.15 =
+= 1.4.16 =
 
 - 强制 endpoint 使用 https