Re: [idn] Re: Back to work (Nameprep) (was: Re: Just send UTF-8 with nameprep (was: RE: [idn] Reality Check))

[Martin Duerst <duerst@w3.org>]

At 11:10 01/07/18 -0400, Keith Moore wrote:
> > Now, let's think about another case of   all-Greek "oo.com" and all-Latin
> > "oo.com":
> > Either of the two consists of scripts from only single character sets.
> > But the two still look very similiar. Do you have any good idea about 
> this ?
>
>first, how likely is this in practice that a label of all Greek letters
>will accidentally collide with a label of all Latin letters?   (as opposed
>to a deliberate collision)

Very low for lower case. Between Latin and Greek, or Cyrillic and Greek,
it's only the 'o'.
Between Latin and Cyrillic, it's the 'a', 'e', 'o', 'p', 'c', 'y', 'x',
plus 's', 'i', and 'j' in some languages.

For upper-case, it's more. Regards,   Martin.



>for second-level domains at least, and for some third-level domains,
>it would make sense for the registry to disallow labels whose appearances
>collide with all-ASCII labels.

Most probably yes.


>there are already some such rules in place
>even for ASCII, these would just be extended.

Can you tell me more about these, or give some pointer?

Regards,   Martin.