Stupid U-label question [correction]

Frank Ellermann hmdmhdfmhdjmzdtjmzdtzktdkztdjz at gmail.com
Tue Aug 19 20:22:04 CEST 2008


Sorry, several typos and an error, new attempt:

| I *think* we have it clear that LDH-label means
| what the name says, a DNS domain label (1..63
| octets) limited to ASCII letters, digits, and
| hyphen; not starting or ending with a hyphen.

[...]

| Let u1 = ä (umlauted a), that's A-label xn--4ca.
| Let u2 = xn--4caä, and use punycode *directly*
| to bypass the RFC 3490 4.1 (5) restriction.
|
| That results in A-label xn--4ca-cxa.  Therefore
| in theory u2 could have A-label xn--xn--4ca-cxa
| IFF that is not prohibited somewhere in IDNA200X.

No u3 involved, I need more coffee.  

 Frank



More information about the Idna-update mailing list