Another complimentary scheme is to use pattern matching - The annotation
acts like an antibody which only sticks to the right part of the document.
By specifying the pattern redundantly, the glue continues to work even if
a few changes have been made to the document since the pattern was defined.
Unfortunately, I haven't had the time to refine this idea. Anybody
interested in taking it further?
[ possible CompSci mini project? ]
Dave Raggett