Need multiple \mark entries over the same barline

[James Harkins]

In some places, I have a \markup-style mark over the same barline, and at 
the same barline, I also want a rehearsal mark (produced by \mark 
\default). Unfortunately it seems only one \mark is allowed at any given 
moment.

This is a type of markup-style marking I mean:

 \mark \markup { \fontsize #-2 { \note #"4." #1 "=" \note #"2" #1 } }

... where you wouldn't want the score to print the duration equivalence 
over every staff, just at the top. And of course rehearsal marks shouldn't 
go over every staff either.

Is there any workaround?

hjh