specifying the vertical extent are described in connection with
the @internalsref{Axis_group_engraver}.
-Example files: @lsr{spacing,page-spacing.ly},
-@lsr{spacing,alignment-vertical-spacing.ly}.
+Example files: @c @lsr{spacing,page-spacing.ly},
+@c @lsr{spacing,alignment-vertical-spacing.ly}.
@node Vertical spacing between systems