Re: Combining characters (was: Re: [idn] hostname historyhell)

[liana Ye <liana.ydisg@juno.com>]

I think  [nameprep] handle them inconsistently, that is 

038F; 03CE; Case map 

and your latter case  <A><acute> ==> > <a><acute> is 
not considered. But: 

0390; 03B9 0308 0301; Case map
0587; 0565 0582; Case map

do use character combination to normalize the symbols.

Liana

On Sun, 25 Nov 2001 13:59:39 +0900 "Soobok Lee" <lsb@postel.co.kr>
writes:
> (resent after correcing some formatting error)
> 
> Does a combining sequence inherit the bicameral  characteristic of 
> the leading letter ?   
> 
> For example,  
> 
> <A acute> can be lowercased into <a acute> ?  Then, <A><acute> ==> 
> <a><acute> ?
> <A><acute><diaeresis>... ==> <a><acute><diaeresis>... ?  I am not 
> sure whether it can be.
> 
> Can <I><dot-above>   be lowercased into <i><dot-above> or not?
> <I dot-above> has no combined form <i dot-above>, but has <i> as its 
> lowercase form 
> due to its language context in turkish and azerbaijani.
> Is this case just an exception ?
> 
> Soobok Lee
> 
>   ----- Original Message ----- 
>   From: Soobok Lee 
>   To: idn@ops.ietf.org 
>   Sent: Sunday, November 25, 2001 1:32 PM
>   Subject: Re: Combining characters (was: Re: [idn] hostname 
> historyhell)
> 
> 
> Does a combining sequence inherit the bicameral  characteristic of 
> the leading letter ?   
> 
> For example,  
> 
>  can be lowercased into  ?  Then,  ==>  ?
> ... ==> ... ?  I am not sure whether it can be.
> 
> Can    be lowercased into  or not?
>  has no combined form , but has  as its lowercase form 
> due to its language context in turkish and azerbaijani.
> Is this case just an exception ?
> 
> Soobok Lee
> 
> 
> ----- Original Message ----- 
> From: "Eric A. Hall" 
> To: "Kenneth Whistler" ; ; 
> Sent: Friday, November 23, 2001 1:33 AM
> Subject: Re: Combining characters (was: Re: [idn] hostname 
> historyhell)
> 
> 
> > 
> > "Eric A. Hall" wrote:
> > 
> > > The specific concern I had is already addressed in nameprep so 
> there
> > > is no need for the exception.
> > 
> > What I am concerned with is the use of domain name which consist 
> entirely
> > of punctuation, or in this case, which consist entirely of 
> combining
> > marks. These represent a rules problem with the principles behind 
> the
> > "safe-set". EG, we forbid domain names like ````````.com using 
> U+0060, but
> > ````````.com may be legal if the combining character U+0300 is 
> used
> > instead.
> > 
> > I get lost in the shrubbery of specs, so can somebody tell me 
> whether or
> > not this is a valid concern? I can't tell for certain what happens 
> at the
> > end of nameprep with such a label.
> > 
> > If this is a problem, a solution might be to change the 
> prohibition
> > against leading hyphen to a prohibition against leading hyphen and
> > combining characters.
> > 
> > -- 
> > Eric A. Hall                                        
> http://www.ehsco.com/
> > Internet Core Protocols          
> http://www.oreilly.com/catalog/coreprot/
> > 
> 
> 
>