DOCBOOK: Implementing Marginalia [was: What should a <sidebar> looklike?]

[Jason Foster <jafoster@uwaterloo.ca>]

Returning to a long-lost topic... Norman Walsh <ndw@nwalsh.com> said:

> No, what you really have there is marginalia, not sidebars. I agree
> with Yann that the most appropriate markup is probably <footnote
> role="marginalia"> or something like that. I don't know of any
> SGML/XML publishing systems that support marginalia, however.

At this point in time I am not sufficiently familiar with XSLT, XSL:FO, or 
the DocBook-XSL stylesheets to add marginalia support to the processing 
chain on my own.  Do you have any suggestions for ways of using existing 
DocBook markup to simulate marginalia?

Marginalia that align with the top of the relevant <para> would be a 
perfectly acceptable solution (I think... gotta ask the boss) right now, 
and for some reason I figure that such an implementation might be more 
straightforward.

In the longer term, what is the "accepted" approach to adding something 
like marginalia to both the DocBook semantics and layout?  My brief look 
at DocBook-XSL 1.48 revealed to me that doing any major work, such as 
placing things in the (I think) "after region", is way beyond my current 
skills.

Thanks for you help!

Jason Foster