Colleagues, I have included Olaf's block diagram (in jpg since I don't have Visio) in place of the earlier version. I also included the second SDL block diagram at the end of the document in the Use Case section (4.2). Is this the right location for this diagram? I generally agree with Sadatoshi's note (and Olaf's response) about duplicating MSC functions. However, I think somehow we need to capture those functions as "shall" statements in the IDC specification. Can we get some guidance from the commercial sector on this? Is it better/would you prefer to simply incorporate by reference the MSC functional requirements or "translate" them into a functional/performance specification (which could be used in a tender or request for proposal)? We are now two weeks away from our meeting in St. Germain en Laye. Please get your comments/recommendations to me as soon as you can. I will make every effort to get them all incorporated in time for the meeting. Best regards Bill Cairns, FRIN Principal Engineer Long Range Identification & Tracking Commandant (G-PWN-3) USCG Electronics Navigation Division William.R.Cairns(a)uscg.mil V: 202-372-1557 F: 202-372-1930