Re: [css3-writing-modes] vertical orientation and UTR50

Koji Ishii wrote:

> > 2. Define the mapping of MVOsimple and SVOsimple in terms of MVO
> > and SVO normatively (it currently is in a note).
> This one turned out to have one issue; the current text has "scripts
> like Mongolian," which looks ambiguous to me to make it normative.
> I'd like it be very specific so that everyone can get the same
> result, and I think "like Mongolian" isn't enough for the purpose. I
> think the HO property serves the best for that purpose. If there
> were any objections to do so, please let me know.

I don't think there's a need for a separate HO property and have
posted a message in the UTR50 forum stating this. [1]  In fact,
there's no role for HO in defining the behavior of the
'text-orientation' property since this property only affects vertical
runs, *not* horizontal runs.  So the sentence starting with "The one
exception..." can be omitted entirely.  In vertical runs, Mongolian
and Phags-pa are displayed upright, just as the MVO/SVO reflects.

The spec needs to normatively refer to MVO and SVO (*not* derived
properties) and let the Unicode discussions resolve the issue of which
values apply to specific codepoints.

Taro Yamamoto from Adobe, who attended the F2F in Kyoto last year, has
posted a very lucid document concerning MVO values.  I think it
reflects nicely some of the concerns of the Japanese typographic

UTR50 forum posting:


John Daggett


Received on Tuesday, 3 July 2012 01:21:39 UTC