Private Use areas - Vertical Text

[James Kass via Unicode]

John Knightley wrote,

> Yes, as Richard says when CJK Zhuang text is displayed
> vertically whilst the Zhuang characters in Unicode remain
> upright, but those with PUA codepoints are rotated 90°.
> This is because the PUA characters are treated like English
> text, which are correctly rotated 90°. ...
>
> ...
> ... the need for PUA Zhuang characters remains, and will
> so for decades to come.

A possible work-around would be to have two fonts for PUA Zhuang, one
for horizontal text and one for vertical.  The one for the vertical
text would have the glyphs in the font pre-rotated 90° anti-clockwise.
This would require font switching when switching from horizontal to
vertical layout, of course.