404. That’s an error.
The requested URL /bookmarks/mark?op=edit&output=popup&bkmk=http%3A%2F%2Fwww.addforums.com%2Fforums%2Fshowthread.php%3Ft%3D139640&title=Understanding+until+suddenly+brain+stops...
was not found on this server. That’s all we know.