diff -Naur wp-signup.php wp-signup.php
--- wp-signup.php	2018-03-19 10:03:05.395551000 +0530
+++ wp-signup.php	2018-03-21 14:04:40.945574101 +0530
@@ -368,6 +368,12 @@
 /**
  * Validate a new site signup.
  *
+ * @global string $blogname The site name.
+ * @global string $blog_title The site title.
+ * @global WP_Error|string $errors
+ * @global string $domain The domain URL.
+ * @global string $path The site root path.
+ *
  * @since MU (3.0.0)
  *
  * @return null|bool True if site signup was validated, false if error.