[MPEG-OTSPEC] An input on the 5th edition

[木田泰夫]

Thank you John for your comments.

Adobe is a member of CITPC and their CJK font experts are active in the group. We’ll incorporate their and others' input into the proposal. Once we submit the proposal we’ll just follow experts’ guidance in terms of the wording :)

How does the timeline look like if we want to propose it for the 5th edition?

thank you!

- kida

> 2023/04/18 2:15、John Hudson <john at tiro.ca>のメール:
> 
> On 17042023 7:59 am, 木田泰夫 wrote:
>> For the 5th edition of Open Font Format, CITPC would like to clarify how it describes ‘palt’.
>> 
>> It states, “If ‘kern’ is activated, ‘palt’ must also be activated if it exists.”.
>> 
>> First, does this sentence represent requirements for fonts? Or does it describe requirements for font rendering and text layout/shaping engines? It needs to be clarified which interpretation is correct.
> 
> This would be a requirement or recommendation for text layout. ‘If it exists’ means if palt is present in the font, and I believe the intent is that kern and palt are intended to complement each other, so if one is active then the other should be also.
> 
> That said, this feature was registered by Adobe, so reflects Adobe’s intentions for how they planned to implement it in their own CJK layout. So...
> 
>> Second, in ISO/IEC, the word “MUST” represents external constraints rather than requirements specified in standards. See 7.2 in ISO/IEC Directives, Part 2. This sentence should be reformulated using “shall”, “shall not”, “may”, and so forth.
> 
> ...there may be disagreement about which word is appropriate in this particular case. Is this a recommendation to layout implementers, or a requirement based on how font developers are expected to implement kern and palt for CJK layout?
> 
> In general, the wording of OpenType Layout feature descriptions in the registry is quite loose and informal, and doesn’t strictly conform to any conventions or directives regarding meaning of specific words. For a long time, there was a question whether the OTL registries were even formally part of the specification, or simply informational appendices.
> 
> As a general observation, I am not sure that the ISO/IEC understanding of ‘must’ corresponds to that I have encountered in font-related specifications, where it tends to represent a strong requirement, regardless of whether due to external constraints. The OFF standard, of course, began life as a direct port of Microsoft’s OpenType font format specification, so its use of terminology in multiple places may not correspond to ISO/IEC directives.
> 
> J.
> 
> 
> -- 
> 
> John Hudson
> Tiro Typeworks Ltd    www.tiro.com
> 
> Tiro Typeworks is physically located on islands
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> of the Snuneymuxw and Penelakut First Nations.
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