DOCBOOK: how to annotate/callout a list of files

["Robert P. J. Day" <rpjday@mindspring.com>]

  i want to list all of the files involved in the linux login process:

  /etc/passwd
  /etc/shadow 
  /etc/group
  /etc/profile

  ... etc etc ...

and would like to assign something like callouts to each file so i can 
expand on each one underneath the list.  but, as i read it, "co"s can't
be attached to list elements.  so it seems i have two choices:

1) do the list as, possibly, a literallayout (which is possible)

2) use an actual list, and maybe attach footnotes (yuck ... that doesn't
   seem like the effect i'm going for.

is there an obvious way to get this effect?

rday