<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;}
@font-face
{font-family:"Cambria\,Bold";
panose-1:0 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:"Calibri\,Italic";
panose-1:0 0 0 0 0 0 0 0 0 0;}
/* 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:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@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="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">I think it was left to specific file format specifications built on OPC to determine how to handle things like this. For example, this is addressed in Part 1:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><b><span style="font-size:13.0pt;font-family:"Cambria,Bold",sans-serif;color:#4F82BE">9.1.4 Unknown Parts<o:p></o:p></span></b></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black">With the exception of relationship parts, all other parts in an Office Open XML document that are not the target<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black">of an implicit or explicit relationship are considered
</span><i><span style="font-size:11.0pt;font-family:"Calibri,Italic",sans-serif;color:black">unknown parts</span></i><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black">. Unknown parts shall be ignored on<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black">document consumption and can, but need not, be discarded on production.</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">John<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> eb2mmrt@gmail.com [mailto:eb2mmrt@gmail.com]
<b>On Behalf Of </b>MURATA Makoto<br>
<b>Sent:</b> Saturday, May 2, 2015 4:05 AM<br>
<b>To:</b> SC34<br>
<b>Subject:</b> Seemingly-orphan parts<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<div>
<p class="MsoNormal">Dear colleagues,<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Is it ok to embed parts in an OPC package without having<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">relationships to them? Such parts may be referenced by the<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">href attribute of some XML element, for example. OPC<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">explicitly allows such references.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"> Parts may contain references to other parts in the<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> package and to resources outside of the<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> package. These references are represented inside<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> the referring part in ways that are specific to<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> the content type of the part; that is, in<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> arbitrary markup or an application-defined<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> encoding. This effectively hides the internal and<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> external links between parts from consumers that<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> do not understand the content types of the parts<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"> containing such references.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Since such references are invisible from OPC implementations<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">or even OOXML implementations (when references appear within<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">application-defined extension elements). Thus, OPC or OOXML<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">implementations should never throw away parts, since they<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">might be used. But I know that implementations do throw away<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">seemingly-orphan parts. We might want to explicitly state<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">that seemingly-orphan parts should not be thrown away.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">Alternatively, we might want to discourage seemingly-orphan<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">parts and thus ad-hoc references without explicit relationships.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Regards,<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">Makoto<o:p></o:p></p>
</div>
</div>
</div>
</div>
</body>
</html>