Codepoints removed between IDNA200X and IDNA2003

Patrik Fältström patrik at
Wed Mar 19 16:19:37 CET 2008

On 19 mar 2008, at 15.37, Simon Josefsson wrote:

>> cp = ToUnicode(ToASCII(cp, UseSTD3ASCIIRules), UseSTD3ASCIIRules)
> Dot (U+002E) is not allowed by IDNA2003-ToASCII either, so I believe
> that line is incorrect.
> Did you run the multiple-label ToASCII algorithm or the single-label
> ToASCII algorithm?  The latter should not permit U+002E.

I called the libidn ToASCII and ToUnicode that exists. Now with the  

I guess you know the author :-)

> The multiple-label ToASCII algorithm is under-specified with regard to
> zero length labels in RFC 3490.  If you follow the strict algorithm as
> explained in RFC 3490, you end up with rejecting strings that end with
> '.', including the string that only contains '.'.

Fine, still, we know the rest of the list is correct then. I.e. we  
know the issues with ".".


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