Rationale: This will allow the MOD author to alter the result of
build_cfg_template, for example if he wants to inject extra information to a certain field that isn't supported by phpBB itself or add an type that isn't support by phpBB itself.
/includes/functions_acp.php, just before
Input arguments: The arguments as passed into the function
$tpl_type, $key, &$new, $config_key, $varsas well the