Front Matter and Back Matter - Input XML fragment

The frontmatter topics are wrapped in an <oxy:front-matter> element, that has the class bookmap/frontmatter (it is a clone of the original <frontmatter> element from the map):

oxy:front-matter xmlns:oxy="http://www.oxygenxml.com/extensions/author" class="- map/topicref bookmap/frontmatter ">
        <concept xmlns:dita-ot="http://dita-ot.sourceforge.net/ns/201007/dita-ot" class="- topic/topic concept/concept "
            id="unique_1" oid="concept-1">
    </oxy:front-matter>