What is `stable' between several exports, is the nesting and the names
of the main containers (replace X with depth of the nesting and ID with
the section number):

  * body
  * content
  * title
  * div id="outline-container-ID" class="outline-X"
  * h1, h2 ...
  * div class="outline-text-ID" id="text-X"

Some containers might or might not exist. E.g. the
 
  * div id="postamble"
  * div id="table-of-contents" (could be placed virtually anywhere)
  * etc.




  Sebastian