[mpeg-OTspec] DAM2 comments

Jonathan Kew jfkthame at gmail.com
Mon Sep 5 22:11:27 CEST 2016

On 5/9/16 20:23, John Hudson john at tiro.ca [mpeg-OTspec] wrote:
> On 03/09/16 17:05, Peter Constable petercon at microsoft.com [mpeg-OTspec]
> wrote:
>> While I don’t have any objection to the goal of categorizing features,
>> “orthographic shaping form feature” sounds like a technical term yet
>> it is nowhere defined. Rather than get into whether to introduce
>> feature meta-properties at this time, I think the field content can be
>> reworded to get at the same point without any terminological issue.
> Andrew uses the term 'Orthographic unit shaping' in the USE documentation.
>> Fourth, the Script/language sensitivity field has this:
>> “Can be used in any script with joining properties specified in the
>> Unicode standard for joining-script shaping [20].”
>> The problem with that is that /every Unicode character/ has a
>> Joining_Type property. The scripts of interest are those with
>> characters that are right-, left- or dual-joining; this can also be
>> characterized as scripts for which Joining_Type properties are given
>> explicitly in ArabicShaping.txt.
> My original draft of the feature revisions explicitly referenced
> ArabicShaping.txt, since the OTWG discussion regarding this concluded
> that these features should be used solely to implement joining as
> specified in that standard. Vlad asked to revise the texts because
> apparently MPEG has issues around referencing external standards.
> Personally, I think the feature descriptions absolutely should reference
> ArabicShaping.txt, because that's what the features are for, and if this
> is a problem in the OFF spec, maybe we should just do it right in OT 1.8.

This would appear to ignore/exclude the use of 'init' in Bengali script, 
as well as being a major change from the existing description of the 
features, which mentions "...common in Latin connecting scripts..." as 
well as scripts like Arabic.

I don't know whether there are many examples where these features have 
been used for cursive behavior in non-Arabic-like scripts (at 
https://www.microsoft.com/typography/otspec/features_fj.htm#fina, use in 
Poetica is mentioned, but I don't know if that was an example of a 
shipping product or just a potential example of where it _might_ have 
been used), but the use of 'init' in Bengali, at least, is 
well-established. Is that to be deprecated? Replaced by something else?


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