How about just having the browser use <A HREF="..." REV="Precedes">...</A>
and if the previous link matches the HREF then go "back", if not, continue
adding things to the history list like normal.
I believe that having servers directly messing with client history lists
is a can of worms that we really don't want to open. Whatever happens
on the client end should be implied by generic hypertext operations.
--sanders