ORO indexes
All indexes in ORO should be captured with display="print" on indexGroup.
Example index
<indexGroup id="acref-9780190456160-indexGroup-1" display="print">
<indexList id="acref-9780190456160-indexList-1" indexListType="regular"><titleGroup id="acref-9780190456160-indexList-1-titleGroup-1">
<title>
<p>Index</p>
</title></titleGroup><p>...</p>
</indexList>
</indexGroup>