<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0in;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;}
span.EmailStyle22
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">On Wednesday, March 25, 2020 4:27 PM John Hudson wrote:<br>
<br>
</span></p>
<div>
<p class="MsoNormal">On 25032020 12:56 pm, Levantovsky, Vladimir via mpeg-otspec wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoListParagraph" style="text-indent:-.25in"><span style="color:#1F497D">1.</span><span style="font-size:7.0pt;color:#1F497D">
</span><span style="color:#1F497D">Lack of font metrics for writing systems other than Western and CJK</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#1F497D">Additional discussions are needed, we may need to consult with outside experts who are familiar with typographic environments of different languages
and writing systems to consider the additional complexities associated with languages like Thai [where glyphs are often composed with multiple marks positioned above and below the base].</span><o:p></o:p></p>
</blockquote>
<p>There are a couple of components to this:<o:p></o:p></p>
<p>1) Script- or language-specific versions of common metrics used for linespacing.<o:p></o:p></p>
<p>2) Script-specific data points that define internal relationships (in the way, e.g. cap height, x-height, ascender, and descender data points define height relationships in European scripts).<o:p></o:p></p>
<p>There has been a lot of prior discussion in the OTWG on (1), and the consensus seems to be that this should be done with a new version of the BASE table, using existing OTL script and language system tags with sets of vertical metrics for linespacing corresponding
to the OS/2 table Typo metrics.<o:p></o:p></p>
<p>(2) has been discussed in various places, but as you say consultation is needed to identify the data points that are useful for each script (which might not always be obvious: much depends on how the data points might be used, e.g. in calculating size and
alignment of 'dropcap' initials in CSS).<span style="color:#1F497D"><o:p></o:p></span></p>
<p><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">[VL] Thank you John,<o:p></o:p></span></p>
<p><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">As it relates to item 2), I am curious if some typographic tools used for certain scripts (drop caps in particular, as they are mentioned in CSS liaison as a use case “A”) can
be considered universally applicable for all scripts; or whether some of these tools (such as drop caps) are strictly a product of typographic norms and traditions that may be commonly used in some scripts but never in others.<o:p></o:p></span></p>
<p><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Vladimir<o:p></o:p></span></p>
<p><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<pre>-- <o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>John Hudson<o:p></o:p></pre>
<pre>Tiro Typeworks Ltd <a href="https://protect-us.mimecast.com/s/N8lQCYEnxytLD28oUGC67y">www.tiro.com</a><o:p></o:p></pre>
<pre>Salish Sea, BC <a href="mailto:tiro@tiro.com">tiro@tiro.com</a><o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>NOTE: In the interests of productivity, I am currently <o:p></o:p></pre>
<pre>dealing with email on only two days per week, usually <o:p></o:p></pre>
<pre>Monday and Thursday unless this schedule is disrupted <o:p></o:p></pre>
<pre>by travel. If you need to contact me urgently, please <o:p></o:p></pre>
<pre>use some other method of communication. Thank you.<o:p></o:p></pre>
</div>
</body>
</html>