<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=utf-8">
<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;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-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;}
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.EmailStyle20
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
span.conform
{mso-style-name:conform;}
.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="color:#1F497D">FWIW, the stripping of DISG is also a necessity for WOFF2. Due to transforms and data pre-processing / optimization steps applied as part of the WOFF2 encoding steps [that invalidate the DSIG], it is required
that “</span><span style="font-size:13.5pt;font-family:"Arial",sans-serif;color:black;background:white">the compliant WOFF2 encoder <span class="conform">MUST remove the DSIG table from an input font data</span>, prior to applying transformations and entropy
coding steps.</span><span style="color:#1F497D">” (</span><a href="https://www.w3.org/TR/WOFF2/#table_format">https://www.w3.org/TR/WOFF2/#table_format</a><span style="color:#1F497D">)
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I’d say let’s deprecate DSIG once and for all.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Vlad<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> mpeg-otspec <mpeg-otspec-bounces@lists.aau.at> <b>
On Behalf Of </b>Peter Constable<br>
<b>Sent:</b> Wednesday, August 26, 2020 9:53 AM<br>
<b>To:</b> Bobby de Vos <bobby_devos@sil.org>; Dave Crossland <dcrossland@google.com>; mpeg-otspec <mpeg-otspec@lists.aau.at><br>
<b>Subject:</b> Re: [MPEG-OTSPEC] DSIG spec issue<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Office has a font service, serving fonts to (recent versions of) Office apps. My understanding is that they strip DSIG tables from fonts in the service. So, I would assume that recent versions of Office shouldn’t require DSIG tables to
enable features in Latin fonts, though I haven’t confirmed that.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This is all product commentary: it can inform whether DSIG may still be relevant for fonts, though of course doesn’t belong in the spec itself.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Peter<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> Bobby de Vos <<a href="mailto:bobby_devos@sil.org">bobby_devos@sil.org</a>>
<br>
<b>Sent:</b> Wednesday, August 26, 2020 6:01 AM<br>
<b>To:</b> Peter Constable <<a href="mailto:pgcon6@msn.com">pgcon6@msn.com</a>>; Dave Crossland <<a href="mailto:dcrossland@google.com">dcrossland@google.com</a>>; mpeg-otspec <<a href="mailto:mpeg-otspec@lists.aau.at">mpeg-otspec@lists.aau.at</a>><br>
<b>Subject:</b> Re: [MPEG-OTSPEC] DSIG spec issue<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p>In addition to triggering the OpenType icon, a DSIG was (is?) needed in older versions of Microsoft Word to process some OpenType features in Latin script fonts.<o:p></o:p></p>
<p><a href="https://protect-us.mimecast.com/s/Wqy2CwpA5KsGM0Z7IqyVTq">https://github.com/googlefonts/fontbakery/issues/1845#issuecomment-564383952</a><o:p></o:p></p>
<p>As recently as Office 2013 this was the case, and Office 2013 has not reached end of life yet.<o:p></o:p></p>
<div>
<p class="MsoNormal">On 2020-08-25 8:01 p.m., Peter Constable wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">I think at one time, yes, but I don’t think that’s been relevant since Windows 7.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Peter<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> mpeg-otspec <a href="mailto:mpeg-otspec-bounces@lists.aau.at">
<mpeg-otspec-bounces@lists.aau.at></a> <b>On Behalf Of </b>Dave Crossland<br>
<b>Sent:</b> Tuesday, August 25, 2020 6:09 PM<br>
<b>To:</b> mpeg-otspec <a href="mailto:mpeg-otspec@lists.aau.at"><mpeg-otspec@lists.aau.at></a><br>
<b>Subject:</b> Re: [MPEG-OTSPEC] DSIG spec issue<o:p></o:p></p>
</div>
<p class="MsoNormal"> <o:p></o:p></p>
<div>
<p class="MsoNormal">Wasn't there something about needing a DSIG table to trigger the OpenType icon in Windows Explorer?<o:p></o:p></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
</blockquote>
<div>
<p class="MsoNormal">-- <br>
Bobby de Vos<br>
<em><span style="font-family:"Calibri",sans-serif"><a href="mailto:bobby_devos@sil.org">bobby_devos@sil.org</a></span></em><o:p></o:p></p>
</div>
</div>
</body>
</html>