I would like to see the advertisement section (2.3) revised to be more prescriptive about how to use the two forms. It seems to me that an XMPP 1.0 stream should only advertise with the old dialback namespace method on the initial stream element of the negotiation in case it's a 0.9 implementation. If the response is a 0.9 stream then keep going in that mode. If the response is a 1.0 stream, it should not include the old namespace and then must include a dialback feature. Not including the feature seems wrong - 0220 only says it is preferred, not required. Preferably, the receiving server would not include the old namespace at all on the stream in response to a 1.0 stream. It just confuses matters. And on stream restarts, the old ns should not be used at all by either side.
Also, why the recommendation to have dialback required and SASL optional if both are advertised? I'm not sure it matters, just curious about the rationale. Seems like the server would mark as required the one that it prefers since it doesn't make sense to do both - sort of a makeshift priority indicator. Dave Richards
