Accessible FXL publication with reflowable fallbacks

package.opf

<?xml version="1.0" encoding="UTF-8"?>
<package xmlns="http://www.idpf.org/2007/opf" prefix="rendition: http://www.idpf.org/vocab/rendition/# cc: http://creativecommons.org/ns#" version="3.0" dir="ltr" id="package">
  <metadata>
    <dc:title>Accessible FXL publication with reflowable fallbacks</dc:title>
    <meta property="rendition:layout">pre-paginated</meta>
    <meta property="rendition:orientation">auto</meta>
    <meta property="rendition:spread">auto</meta>
    <meta property="schema:accessMode">textual</meta>
    <meta property="schema:accessMode">visual</meta>
    <meta property="schema:accessModeSufficient">textual,visual</meta>
    <meta property="schema:accessModeSufficient">textual</meta>
    <meta property="schema:accessibilitySummary">This publication contains alternate resources that are fully accessible for every page.</meta>
  </metadata>
  <manifest>
    <item id="ch1" href="page1.html" fallback="ch1-reflow" media-type="application/xhtml+xml" />
    <item id="ch1-reflow" href="page1-reflow.html" media-type="application/xhtml+xml" properties="rendition:layout-reflowable" />
  </manifest>
  <spine page-progression-direction="ltr">                
    <itemref id="page1" />
  </spine>
</package>