Dear RIPE: Please don't encourage phishing

Jimmy Hess mysidia at
Mon Feb 13 03:52:16 UTC 2012

2012/2/12 Masataka Ohta <mohta at>:
> Valdis.Kletnieks at wrote:
> So, I can understand your attempt to insist on lowercase,
> but it does not work because DNS does not allow it.

Not exactly...  DNS is case-insensitive when you are talking about
7-bit ASCII;  the set of alphabetic characters that can appear in a
DNS label;  with no punycode.

IDN means that non-ASCII characters are represented using punycode.

As soon as you have a browser parsing  punycode stuff,  any string
containing unicode characters has a unique punycode encoding / RFC
3491 / RFC 3492.

The symbols represented in the punycode encodings are not case sensitive.

Uppercase A-Z  vs Lowercase a-z in the generalized variable-length
integers   are not distinct,
the punycode representation itself cannot really be case sensitive,
but the codepoint represented by the encoding,  the result of decoding
the punycode  is case-preserving.


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