The instructions showed to the user when registering on the XMPP transport currently suck.
"Please enter your XMPP JID and password as it's used on the XMPP server pointed to by the transport."
"JID" should be replaced by something more human.
The instructions are written to be read by the administrator of the transport. However, it are end users who will have to read this text and they will not know to which XMPP server the transport points!!
The word "Please" is unecessary and may make the dialog larger in some clients. This is especially important on devices with a small screen (e.g. cell phone).
"It's" is informal, isn't it? :o)
At least the full version ("Jabber ID") is more descriptive, but I prefer "Contact ID" (this will also be good for consistency with the rest of Coccinella's UI).
Allow people to enter any JID (not only 1 preconfigured server). If this is not possible to do very soon, at least tell the user which server the administrator configured!
Delete this word.
Replace /it's/it is/