Re: [idn] I-D ACTION:draft-ietf-idn-idna-08.txt

["Adam M. Costello" <idn.amc+0@nicemice.net.RemoveThisWord>]

Mark.Andrews@isc.org wrote:

>       I don't know what's "unclear" or "silent" about the following
>       from RFC 1035.
>
> Although labels can contain any 8 bit values in octets that make up
> a label, it is strongly recommended that labels follow the preferred
> syntax described elsewhere in this memo, which is compatible with
> existing host naming conventions.  Name servers and resolvers must
> compare labels in a case-insensitive manner (i.e., A=a), assuming
> ASCII with zero parity.  Non-alphabetic codes must match exactly.

How do I "compare labels assuming ASCII with zero parity" when the input
strings are not ASCII or don't have zero parity?  If I can really assume
zero parity, then I can ignore the 8th bit completely and compare only
the bottom 7 bits.  On the other hand, "match exactly" suggests that I
should require the 8th bit to match too.  But even then, among the codes
128..255, which are non-alphabetic?  I don't know, but I'm required to
do a case-insensitive comparison, so I'm screwed.

Is that unclear enough for you?  :)

AMC