text/sitemap

[1] XLIFF 1.2 Representation Guide for HTML (2008-01-03 05:12:05 +09:00 版) <http://docs.oasis-open.org/xliff/v1.2/xliff-profile-html/xliff-profile-html-1.2-cd02.html#elem_object_param>

<UL>
  <LI>
  <OBJECT type="text/sitemap">
  <param name="Name" value="Product Identification">
  <param name="Local" value="ProductIdentification.htm">
  </OBJECT>
  </LI>
  <LI>
  <OBJECT type="text/sitemap">
  <param name="Name" value="Features">
  <param name="Local" value="Features.htm">
  </OBJECT>
  </LI>

[2] 5.7. Sitemap formats (2015-10-29 22:41:00 +09:00 版) <http://www.nongnu.org/chmspec/latest/Sitemap.html>

The <BODY> tag contains an <OBJECT> tag that stores properties of the file in <param> tags, followed by a <UL> tag, whose <LI> tags have <OBJECT> tags that store the properties of the Contents/Index items in <param> tags. e.g.:
<BODY>
<OBJECT type="text/site properties">
<param name="Property Name" value="Property Value">
…
</OBJECT>
<UL>
<LI> <OBJECT type="text/sitemap">
<param name="Property Name" value="Property Value">
…
</OBJECT>
…
</UL>
</BODY>