David, This is exactly the point that I tried to make in responding to an earlier message from David F. The NRR issue is tied directly to the issue of boundaries. I believe that the answer is to ensure that readers understand that we have bounded the specification from MSH to MSH, not application to application. I believe that the T1 input that was provided to the list last week does exactly that. By the way, I have not seen any comments on the intitial contribution beyond Chris--your thoughts? Ralph Berwanger