I think we should add XMPP Security Labels to the list of extensions which should not be used with RTT, at least not with careful consideration and a specification detailing exactly how the labels are to be used.
In short, Security Labels in XMPP are designed based upon Security Labels in E-mail, both of which are message-based communication facilities. RTT, however, is quite conversation oriented. And this difference creates some interesting semantic and user experience issues that would have to be carefully considered. Until that's done, the best thing to do is recommend against using Security labels with RTT. -- Kurt
