[mpeg-OTspec] DAM2 comments

John Hudson john at tiro.ca
Mon Sep 5 21:23:10 CEST 2016

On 03/09/16 17:05, Peter Constable petercon at microsoft.com [mpeg-OTspec] 

> 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.

I like your revision of the Function section, Peter.



John Hudson
Tiro Typeworks Ltd    www.tiro.com
Salish Sea, BC        tiro at tiro.com

Getting Spiekermann to not like Helvetica is like training
a cat to stay out of water. But I'm impressed that people
know who to ask when they want to ask someone to not like
Helvetica. That's progress. -- David Berlow

More information about the mpeg-otspec mailing list