anchor.diff:  reflect this (by using the same keyword to register their effects with
   the show), when you activate one, the other cues which use the same
   keyword are dimmed. This is a hint that when you activate one of them,
  -it will _replace_ the one you just started, rather than running at the
  +it will _replace_ the others, rather than running at the
   same time.
   
   The show may have many more cues than fit on the screen at once; the
  
positive.code: buttons of your controller, while simultaneously being able to control
  others via the screen and mouse. To do that, simply use the link menu
  to turn off the link.
  
negative.code: the larger grid. If there are more cues available in a given
  direction, that arrow will be enabled, otherwise it is dimmed.
  Clicking an active arrow scrolls the view one page in that direction.
  In this grid, it is currently possible to scroll up and to the right.
  
  image:assets/CueScroll.png[Show control,align="right"]
  
  