The Atom community doesn't like the Yahoo! RSS interface in Yahoo! Mail. It's invalid. No interop. Wait! It's an internal interface, not an external interface. If Yahoo! wants to change the semantics of RSS for an internal project, then why should we care? Why should Yahoo! care what the community says about their internal interface. Now, if Yahoo! was trying to interface with external applications, then funky RSS wouldn't be a best practice, but since it's just internal, then if it works, it works. Intertop is not a priority.