RE: [idn] Forbidden characters

[Yves Arrouye <yves@realnames.com>]

> If we define that nameprep must be done before names are sent 
> over the DNS protocol we get a lot of characters that are 
> forbidden in host names.
> 
> For example: all upper case letters, double width and circled letters.
> 
> This is quite a change from current usage where both upper 
> and lower case is allowed in host names.

They are not forbidden: they will get folded to something else. So you can
still write and register your names with, say, U+00DC LATIN CAPITAL LETTER U
WITH DIAERESIS and U+2462 CIRCLED DIGIT THREE. They can be used in your
applications and by your users. They are just strictly euqivalent to U+00FC
LATIN SAMLL LETTER U WITH DIAERESIS and U+0031 DIGIT ONE. Just like 'A' and
'a' are strictly equivalent today in DNS.

YA