adding a generic sibling to high level book children (preface, part,chapter, appendix, etc.)

In DocBook 4.5, ackno has inline-level content and can
only appear at the end of article. I have seen a need
for an acknowlegements element in books, as a sibling to
chapters.

The proposal for DocBook v5.0 is to remove the ackno element,
add an acknowlegements element, and give it a content
model like that of dedication.  Also allow that element
in article.

A straw poll on the TC showed 6 in favor and 1 opposed (Norm thinks it 
is a bad idea).

Some of the front matter materials have very specific semantics 
(dedication for example), so I would not advise overloading that element 
and using a role attribute (e.g., <dedication role="acknowledgements">). 
The same situation occurs with preface. What if you need a preface, 
foreword and introduction? Do you overload preface?

Another consideration was a more general element that
could use a class attribute to distinguish between them. For example, 
class="dedication" and class="acknowledgements" and perhaps others.

In this way, we could potentially consolidate some of these existing 
front and back matter elements, while providing a generic structure to 
meet future needs without having to adopt new elements.

What would you call such a structure?

Thanks and best regards,

--Scott