UAX #9: applicability of higher-level protocols to bidi plaintext

[Eli Zaretskii via Unicode]

> Date: Sat, 14 Jul 2018 13:09:11 +0300
> From: Shai Berger <shai at platonix.com>
> Cc: Eli Zaretskii <eliz at gnu.org>
> 
> I have no argument with this, but I do think that in such cases it is
> wrong for the app to pretend that it is still treating the text as
> plain.

What is "plain text" in this context?  Does, for example, text with
bidi formatting controls count as "plain"?

> If it is an email client, it should use a mime-type such as
> (just inventing something here) "text/plain:ltr" instead of
> "text/plain".

As long as such mime-types don't exist, we cannot use them, right?

> Emacs should have an LTR-defaulting "Log mode" for log
> files, while keeping the UBA default for Text mode.

That's exactly what Emacs does.

> With the current definitions and FAQ, plain text is simply not a
> viable option for intercahnge whenever BiDi is involved. The only
> upside I see for them is, essentially, what Eli and Richard noted: The
> possibility for improved performance in fringe use-cases. I
> repeat/rephrase my original question: 

I don't think those use cases are fringe, FWIW.