WordPress Version: 4.6
/**
* Returns the URL that allows the user to register on the site.
*
* @since 3.6.0
*
* @return string User registration URL.
*/
function wp_registration_url()
{
/**
* Filters the user registration URL.
*
* @since 3.6.0
*
* @param string $register The user registration URL.
*/
return apply_filters('register_url', site_url('wp-login.php?action=register', 'login'));
}