Different Bidirectional Character Types

[Richard Wordingham]

On Sun, 03 Jul 2022 08:04:17 +0300
Eli Zaretskii via Unicode <unicode at corp.unicode.org> wrote:

> > Date: Sat, 2 Jul 2022 21:46:52 +0200
> > Cc: unicode at corp.unicode.org
> > From: Hans Åberg via Unicode <unicode at corp.unicode.org>
> >   
> > > For numbers, using natural language, you don't mean LTR, but
> > > 'with the most significant digit on the left'.  
> > 
> > I asked some Arab speaking how they think about it when writing
> > numbers, and they said they indeed think about it as writing LTR,
> > and not RTL with changed endianness. In a file with RTL/LTR
> > markers, by this, the digits get the same order. I assumed this is
> > how Unicode represents it, but it would be nice with clarification.
> >  
> 
> I thin UAX#9 clarifies it perfectly: numbers are displayed in LTR
> order.

But Hans is forwarding an answer as to which digit comes first when
divorced from computers.

The order of writing can in general be quite variable.  For example,
although the ordering vowel then tone is widely taught in Thailand, at
least for vertical stacks, I've seen evidence of people trying to write
the marks in a Tai Tham stack <base, tone, debatable mark above, vowel
below or maybe subscript consonant>.  (The marks were TONE-1, MAI KANG
and then SIGN OA BELOW.  Many people want to write the last of these
<SAKOT, LETTER A.) If you ask Thais to spell out ไป <U+0E44, U+0E1B>,
seventy years ago they would have said the consonant first; nowadays,
they usually say the preposed vowel first.  The fine details of the
old scheme seem to be lost.

Richard.