[tei-council] Outcome of TEI Council discussion on Text Directionality

[Martin Holmes]

Hi all,

This is a joint message to the TEI Council list and to the Text 
Directionality Working Group list.

We had a TEI Council meeting in Providence a couple of weeks ago, and I 
made a presentation on the work we've done so far on text 
directionality. The slides of the presentation are here:

<http://wiki.tei-c.org/images/4/48/Text_directionality.pdf>

and the minutes from the Council meeting are here:

<http://www.tei-c.org/Activities/Council/Meetings/tcm54.xml#body.1_div.1_div.3_div.1>

At the meeting, I made the following three proposals:

1. That we ignore Unicode for the moment, mainly because it's not 
relevant for us (UTR #20 Unicode in XML and other Markup Languages
advises that bidi embedding (and presumably isolate) control characters 
NOT be used in XML markup), and because it's moving VERY slowly on 
vertical orientation anyway (recent UTR #50 revisions have considerably 
reduced its scope in this regard).

2. That we formally adopt CSS Writing Modes, and provide examples of how 
to use it through the @style attribute.

3. That we create @rotate-x, @rotate-y and @rotate-z attributes to 
capture all manner of rotation (which can also help to handle edge-cases 
of directionality such as boustrophedon).

There was a generally favourable reaction to all three proposals, and I 
was tasked with summarizing them to the Council list and to the working 
group, which I'm now doing.

These were some issues that Council would like to see addressed:

1. CSS WRITING MODES AND BOTTOM-TO-TOP SCRIPTS:

It's notable that the CSS Writing Modes draft explicitly excludes 
bottom-to-top vertical text: "Inherently bottom-to-top scripts are not 
handled in this version. See [UTN22] for an explanation of relevant 
issues." I personally don't see anything in UTN22 that justifies this 
exclusion, and indeed very recent changes to CSS Writing Modes seem to 
be designed to fudge some accommodation for bottom-to-top into the 
system: "The ‘sideways-left’, ‘sideways-right’, and ‘sideways’ values of 
‘text-orientation’ are provided for decorative layout effects and to 
work around limitations in CSS support for bottom-to-top scripts."

Council asked me to contact the W3C working group and clarify the 
exclusion of bottom-to-top scripts. Before I do that, I've been trying 
to figure out if there's any existing discussion of it on their public 
discussion list: <http://lists.w3.org/Archives/Public/www-style/>. I'd 
appreciate any help with this that you have time to give.

If the specification is leaving out bottom-to-top because of the lack of 
sufficient scripts in Unicode that are oriented that way, then maybe 
Debbie can let us know whether there are more bottom-to-top scripts on 
the road for inclusion in Unicode; we might be able to use that as an 
argument for more robust support for it in CSS Writing Modes.

2. PROPOSAL #3: WHAT ELEMENTS SHOULD HAVE THESE NEW ATTRIBUTES

Currently, the TEI @rotate attribute (which really means rotate-z, 
rotation around the z axis) is available only on <zone>. The three 
attributes we propose, one of which would replace it, would be provided 
as a class. The question is what elements should be members of that class.

  - The most conservative approach would be to keep it only to <zone>, 
so you could only use rotation if you're using the Facsimile module.

  - Another would be to say that rotational features are inherently 
topographical, and therefore all suitable elements in the genetic 
editing set (<line> etc.) might also bear them.

  - Most liberally, we might say that these rotational attributes may be 
essential in any kind of transcription, so they should be available on 
any transcription-bearing element in <text> or <sourceDoc>.

I'd be grateful for your feedback on this, and any insights anyone can 
glean from the W3C style list archives regarding bottom-to-top text.

Cheers,
Martin




-- 
Martin Holmes
University of Victoria Humanities Computing and Media Centre
(mholmes at uvic.ca)