It may be just a typing error or more likely the standard has been withdrawn
We retain withdrawn standards for some time, but it is not practical to keep then 'for ever'.
After a standard is removed, any visitor looking for that standard would normally get a bald 'Error 404 : Page Not Found' message, which is not very helpful. Hence this page explains the problem and gives you some options
♦ we get hundreds of wp-login.php requests, which naturally finish up here as we are not a WordPress website. We understand this 'problem' can only be resolved by these visitors changing their local WordPress settings. However if anyone knows of a 'work-around' to this problem, please send us an e-mail