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<p class="MsoNormal">Dear AHG members,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I received an annotated copy of the 3<sup>rd</sup> edition OFF text with user comments. While few of those comments are irrelevant, and many comments have already been addressed in the 4<sup>th</sup> edition text, some of them do need to
be considered for further discussion. Upon reviewing the comments and the text I also came up with few additional questions; among them:<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Question about clarifying version numbers encoded in Fixed format, in particular about providing an example of how e.g. version 1.11 should be encoded;<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Question about the normative scope of uint16 version numbers, and whether the requirement to treat it as a minor version number (and consider all format changes as compatible extensions) should be considered as a mandate or as a recommendation
(as it is now defined as “should”);<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>In “Calculating checksums” section – [editorial] suggestion to replace “the hex value B1B0AFBA” with 0XB1B0AFBA;<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Definition of lineGap in ‘hhea’ table – question on whether historical references to Win 3.1 and MacOS 6 and 7 still need to be preserved;<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Definition of maxStackElements in ‘maxp’ table – question about using a footnote instead of simply including it as part of the description;<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>‘kern’ table, Format 0 – the description states that it is the only format (!) that will be properly interpreted by Windows and OS/2 – do we still need to state this?<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>LookupFlag Bit enumeration table – the first table column should probably have title “Value” instead of “Type”<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>GPOS table description – many table headers have “Value / Type / Description” columns, which is incorrect and should be revised to match other table definitions using “Type / Name / Description” format.<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>GPOS Example 5 – needs review as I suspect Class2Count field has redundant comments.<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>General comment: there are quite a few figures used in the OT/OFF text that show text rendered in low quality, low resolution bitmaps (e.g., see first three sections of
<a href="https://www.microsoft.com/typography/otspec/base.htm">https://www.microsoft.com/typography/otspec/base.htm</a> and many other figures including illustrations for GSUB/GPOS/JSTF tables). Maybe it is the time to redo them – will need a lot of work but
it’s a bit awkward when a document describing font format for high-quality text rendering uses low-res, low quality images as illustrations.
<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Recommendations: It may be a good time reconsider parts of the “Recommendation” section as some of them seem to be requirements (e.g. Big Endian byte ordering, table alignment, etc.) and some of them (e.g. device resolutions) may be
outdated and no longer relevant.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you,<o:p></o:p></p>
<p class="MsoNormal">Vladimir<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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