> If I send a threaded reply and your XMPP client doesn’t support that, then what? I don't know how XMPP works, but a well designed protocol would be backward

> If I send a threaded reply and your XMPP client doesn’t support that, then what? I don't know how XMPP works, but a well designed protocol would be backwards compatible such that threaded messages would simply be normal messages in older clients. Here, those with the old clients would still get something useful while those with new clients get the full experience.