[HarfBuzz] Why mark glyphs are skipped when MarkBasePos matching?

[Richard Wordingham]

On Wed, 27 Mar 2019 14:55:07 +0900
Shusaku KIMURA <skimura0 at gmail.com> wrote:

> So that means Uniscribe also has behaviors not described in the
> specification, even though Uniscribe is implemented by Microsoft who
> is the writer of the specification. Is it correct?

Yes.  And script-specific rendering is particularly bad for this.

> Anyway, I get that there are no documents which is absolute and
> trustworthy for the implementer. Are there any contacts to report such
> unclearness or ambiguity of the specification?

For the specifications at https://docs.microsoft.com/en-gb/typography/,
there is a feedback mechanism which keeps the feedback at
https://github.com/MicrosoftDocs/typography-issues/issues.

The font format specification is now a free ISO standard,
ISO/IEC 14496-22. ISO-related discussions may emerge on the OpenType
list, for which the subscription information is,
"opentype-subscribe at indx.co.uk".  Technically, the font format is just
data which a rendering engine employs, which means that a font does not
specify how text is rendered!  This is trivially true of the
detailed form of glyphs, where optional features such as ClearType and
hinting can be significant.

Richard.