text markup for long multi-measure rests

[John Williams]

How to I attach text markup to long multi-measure rests?

I've looked at multi-measure-rest-text.ly, but it only contains examples
for *single-measure* multi-measure rests.  I want to do something like
this:

     \property Score.skipBars = ##t
       R2.*20_"Tacet"

Perhaps something like that should be added to multi-measure-rest-text.ly.

~ John Williams