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

[Soobok Lee]

(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: [EMAIL PROTECTED] 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" <[EMAIL PROTECTED]> To: "Kenneth Whistler" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> 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/ >