[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [idn] length restrictions on IDN label
At 3:56 PM +0900 10/13/02, Soobok Lee wrote:
[ When i read IDNA draft today, I still can't find
It is indeed covered in the draft. The input to IDNA is code points,
not encoded characters. As you point out, different encodings give
different lengths for the same string. The only lengths that matter
are those that are already in STD 13.
the answer from it for the following question about IDN label length.
If the following issue is already addressed in the draft, please
correct me. ]
Many internet applications impose/assumes the 63-octets-limit of
Which Internet applications are you speaking of? Which encodings are
they using? As you pointed out, different encodings give different
lengths. Thus, no sensible application could assume a 63-octet length
if it deals with different encodings.
IF this assumption is violated, the label will be regarded as invalid
labels, and produce unpredictable errors by some implementations.
From implementators' point of view, more precise specificiation is needed
It seems likely that most implementers can understand that they must
continue to follow the same rules that they always have for the
length of domain names and labels.
about whether IDN label/FQDN has *NEW* length restrictions in
various char encodings,
if IDNA tries to extend the character repertoires of allowable characters.
--Paul Hoffman, Director
--Internet Mail Consortium