Re: [idn] case folding

[James Seng <jseng@pobox.org.sg>]

"Brian W. Spolarich" wrote:
>   Given our general goal of absolutely needing backward compatibility,
> this is an important requirement.  The apparent complexity of generalizing
> a case-folding scheme that will work in all, or at least enough cases to
> warrant its use, points in my mind to avoiding case-folding in future
> protocols.

Agreed. It is a difficult situation. But then again, it only occurs when the
data is used in processing such as domain name.

>   Perhaps this should come down to two separate issues:  the protocol, and
> convention of use.  The protocol should say something like "For backward
> compatibility case-folding is supported for names in the character set
> supported in the original versions of the proctocol.  Case folding however
> is not supported for other character sets."

It is an idea for a protocol. Would you have the time to write an I-D and
describe how all the different aspect of name matching fitting into your idea?
I am very interested to see how we can resolve this problem without resorting
to canonicalization & foldings.

>   The convention of use should then say something like "We recommend that
> names be used in the system in lower case form if the associated language
> and character set supports such a convention."

Or in another sense, the "most insignificant canonicalized form"
 
>   For domains that are generally controlled by a registrar organization it
> would be relatively straightforward for the registrar to prevent, or at
> least strongly discourage, registration of names that violate this
> guideline.  For namespaces that are locally-controlled there's nothing
> preventing users from potentially shooting themselves in the foot, but
> that's the case today and it wouldn't be any worse than many other
> Internet protocols and implementations.

Correct. It is common to see www_1.foo.com and www_2.bar.org. *sigh* And there
is nothing much we can do to prevent this hitting the wire...so we just have
to deal with it.

-James Seng