Re: [idn] Unicode tagging

[Frank Ernens <fgernens@enternet.com.au>]

Paul Hoffman wrote

> > > >In an RFC822 parser, a mailbox can't be KC-canonicalized immediately
> > > >because "_" is a compatibility character which expands to an
> > > >underlined space (entirely logical, IMO).
> > >
> > > This statement is false. U+005F has no compatibility decomposition.

Quite so, I was looking at Unicode 2.x. It doesn't any more.

And James Seng wrote

> For a while, I was stunned wondering how "_" would be affected by NFKC.
> 
> Now, Email is not really part of the work, i suppose it is related and
> it may be important think _think_ about it, altho we may not do anything
> about it.

I meant this only as a counterexample to an argument and chose it
for familiarity, not because I thought we should discuss email.
The example was screwy in several ways, so please ignore it.