--On Monday, 07 July, 2008 15:03 -0700 Karl Auerbach <karl@xxxxxxxxxxxx> wrote: > > I guess you've heard the old joke which asks "How could God > create the world in only seven days? - Because He had no > installed base." yes. But six. He could then rest, rather than dealing with irate users. > If we move this thread up one level of abstraction much of the > conversation is asking the question of how strongly we respect > the installed base of software out there on the net. > > Do we have any principles we can use to guide our choice of > where we put the needle along the continuum from "no change, > no way" to "any and every change is allowed"? Apropos to your opening comment, it is probably ultimately a matter of religion. And mine, FWIW, it that, in cases where it is hard or impossible to prove that their will be no ill-effects on that portion of the installed base that conforms to existing standards, I'm inclined to argue for a very high level of demonstration that there are no ways to do whatever is wanted within the existing models. Such demonstrations may be persuasive that problems that may be lying in wait for us are worth the risks. In their absence, it is hard for me --religiously or pragmatically-- to accept the view that possibly-significant risks are worth it. I note that, because of the caching issue as well as several others, I have never found the position that "we know that COM could be expanded well beyond original design expectations, therefore the root can be" particularly persuasive. Of course, if one is unpersuaded by the potential for risks to the installed base, then one would position oneself to try to get those who are concerned about those risks to prove that they exist. john _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf