Re: [idn] Suggested clarifications of the IDN requirements document

[Harald Tveit Alvestrand <alvestrand@cisco.com>]

At 13:41 09/08/2000 -0400, Keith Moore wrote:
> > Change to
> >
> > [2.5] The DNS protocol (the packet formats that go on the wire) MUST NOT
> > limit the codepoints that can be used.
> > A service defined on top of the DNS, for instance the IDN-to-Address 
> function,
> > MAY limit the codepoints that can be used.
> > The service description MUST describe what limitations are imposed.
>
>this is mostly okay with me, though I still don't see where the
>MUST NOT requirement derives from.

future-proofing.

if, for instance, one were to mandate 16 bits per character, no surrogates, 
that would limit the codepoints unacceptably.
same if the protocol reserved octet values for specific purposes unrelated
to codepoints, making it impossible to use those codepoints.
We might find out 5 years down the road that we DO need to have EM SPACE or 
the BOM represented on the wire, even if we now think both are foolish to 
use in domain names.

I don't know how to express this better.

                 Harald



--
Harald Tveit Alvestrand, alvestrand@cisco.com
+47 41 44 29 94
Personal email: Harald@Alvestrand.no