MyBB Community Forums

HTTP header #404 "page not found" should be sent when there is no thread with such tid.

$thread = get_thread($mybb->get_input('tid', MyBB::INPUT_INT));

if ( !$thread )
	http_response_code(404);

in showthread.php will do it.

It is good for search engines bots not to index such pages (usually deleted). I just had google to point me on such page (through webmater tools).

This should be expanded to include no such user, no such calendar, etc.