Suppose we deploy uppercase IDNs. This could turn out to be a mistake--- in fact, a complete disaster---because uppercase Alpha looks just like uppercase A. We won't be able to fix the mistake, because people will already be relying on domain names that contain Alpha.
Suppose, on the other hand, we initially prohibit uppercase IDNs. If this turns out to be a mistake, we can fix it later, adding support for uppercase IDNs, without breaking anything. Dan Oscarsson writes: > If we are not going to support case-insensivity and case preserving in > responses, then we should turn it of for ASCII too. Deprecating uppercase ASCII is fine. Of course, caches and servers will have to continue accepting uppercase ASCII for compatibility, but users shouldn't type any new names in uppercase. > It *is* a requirement that case-insensitivity shall work for all letters. > That has been the DNS standard so far. That is what people expect. ``It *is* a requirement that host names shall be ASCII. That has been the standard so far. That is what people expect.'' Stupid argument. ---Dan
