diff --git a/code/web/public_php/login/r2_login.php b/code/web/public_php/login/r2_login.php
index 48b2e2694..9f4ff1ab2 100755
--- a/code/web/public_php/login/r2_login.php
+++ b/code/web/public_php/login/r2_login.php
@@ -130,8 +130,22 @@ function err_callback($errno, $errmsg, $filename, $linenum, $vars)
     // Never die after an error
 }
 
-// $reason contains the reason why the check failed or success
-// return true if the check is ok
+/**
+ * @param string $login
+ * The user login.
+ * @TODO: This should become the password.
+ * @param string $password
+ * The user's password.
+ * @param string $clientApplication
+ * @param ? $cp
+ * @param int $id
+ * @param string $id
+ * @param string $priv
+ * @param string $extended
+ * @param string $domainId
+ * @param string $lang
+ * @return true if the User is valid
+ */
 function checkUserValidity($login, $password, $clientApplication, $cp, &$id, &$reason, &$priv, &$extended, &$domainId, $lang)
 {
     global $DBHost, $DBUserName, $DBPassword, $DBName, $AcceptUnknownUser;