I'm a new RICO user. So far I like it allthough my lack of javascript 
knowledge held me up.

I am wonder why the need to register the target elements?  When the 
server returns  the XML stream it names the target element (I use both 
div and span)
The current registerElement has the ability to redirect the html 
response to another target which provides smoe nice separation between 
the server and the browser. You can change the browser code without 
changing the server code.

I suggest that if no element is registered than the default is to target 
the element named in the XML response tag.  This would make the browser 
side code simpler.  There should be better error reporting and error 
mechanisms to go along with this.

In an answer to my own posting, I modified my RICO source to do a 
dynamic look up of the target html element based the ID name specified 
on the xml response tag.
Seems to work just fine. I would question the use of the register call 
unless there is a need to redirect the response to a target other than 
what is specified in the xml response tag