RE: [idn] stringprep comment 5: hangul conjoining sequence

["Kent Karlsson" <kentk@md.chalmers.se>]

> -----Original Message-----
> From: owner-idn@ops.ietf.org 
> [mailto:owner-idn@ops.ietf.org]On Behalf Of
> Adam M. Costello
> Sent: den 11 februari 2002 22:49
> To: idn@ops.ietf.org
> Subject: Re: [idn] stringprep comment 5: hangul conjoining sequence
> 
> 
> Kent Karlsson <kentk@md.chalmers.se> wrote:
> 
> > Compatibility (non-conjoining) Hangul letters are best prohibited.
> 
> Stringprep does normalization before prohibition, so prohibiting
> compatibility characters would have no effect.  After the 
> normalization
> step, there are no compatibility characters in the string.


Ouch!  That leads to results that are completely off the board:
NFKC or NFKD on Hangul compatibility letter sequences leads
to completely wrong results; in particular the distinction between
lead and trail consonants becomes just plain wrong.


> A trick you could play, however, would be to map the characters in
> question to an arbitrary prohibited character that survives the
> normalization step (like U+0000).

Ok, consider that my revised suggestion.

		Kind regards
		/kent k


> AMC
>