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

[Richard Wordingham via Unicode]

On Mon, 16 Jul 2018 10:53:03 +0300
Shai Berger via Unicode <unicode at unicode.org> wrote:

> What I'm not OK with is:
> 
> !Hello, World
> 
> Which is what you'll see if your editor decides to use RTL
> directionality for this file, as the FAQ says it may.

Using 'left aligned' for RTL and 'right aligned' for LTR are 'marked'
styles; they are not appropriate for uninterpreted plain text.  Thus if
text is to displayed as left aligned, LTR defaults are appropriate.
With RTL default and right alignment, what looks like

                                                     !Hello, World

is much more acceptable for "Hello, World!".

An interesting ambiguity is "!True" v. "True!".  "!True" can be read as
"Not true".

The solution may be to encourage the determination of the (default)
paragraph direction from the first paragraph for implementations with
only one margin.  I am not sure if this behaviour is 'standard
compliant'.

Richard.