Re: [idn] nameprep2 and the slash homograph issue

["Adam M. Costello" <idn.amc+0@nicemice.net.RemoveThisWord>]

Erik van der Poel <erik@vanderpoel.org> wrote:

> Another argument against banning the slash homograph is that any new
> banning would require a new ACE prefix, which is a lot of work, and,
> as John said, there should be a high threshold for any demonstration
> that tries to show that a new prefix is necessary.

An alternative, rather than banning the character, is to recommend
that it not be shown; the ACE form could be shown instead.  This would
effectively make the character useless in domain names (for both
phishers and honest folks) without requiring a new ACE prefix.

We could push ToUnicode down inside a wrapper function, ToDisplay.
Applications would never call ToUnicode directly anymore.  Whenever
they wanted to display a domain name, they'd call ToDisplay, which
would call ToUnicode, check the result, and if it didn't like it, call
ToASCII.  (Of course, since ToUnicode typically calls ToASCII, there are
opportunities to optimize that logic.)

AMC