Re: [idn] Unicode tagging

[Keith Moore]

> >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.

and what you can put in an RFC822 address has nothing to do with this group.

Keith