Wrong sequence for Arabic ligature marks(FC5E-FC62, FCF2-FCF4)

[Richard Wordingham]

On Fri, 18 Feb 2022 14:37:50 -0700
Doug Ewell via Unicode <unicode at corp.unicode.org> wrote:

> The vast majority of characters in the Arabic Presentation Forms-A
> and -B blocks should not be used. They exist for compatibility with
> older platforms that did not implement proper Arabic shaping and
> directionality. Instead, use normal Arabic letters from the regular
> Arabic, Arabic Supplement, Extended-A, or Extended-B blocks.

Irritatingly, I had to use some of these characters just this week
because the shaping in Arabic fonts for basic installations of Windows
10 and Ubuntu didn't include the ligatures we were discussing - in
particular that of U+FCCA ARABIC LIGATURE LAM WITH HAH INITIAL FORM.
(The ligature was germane to the discussion.)  Many of the ligatures are
not essential for proper shaping. I've now found and lawfully installed
a font that gives me the ligature from normal Arabic letters.

Richard.