+ "Order grobs from top to bottom, left to right, right to left"
+ " or bottom to top. For vertical alignments of staves, the"
+ " @code{break-system-details} of the left"
+ " @internalsref{NonMusicalPaperColumn} may be set to tune"
+ " vertical spacing. Set @code{alignment-extra-space} to add"
+ " extra space for staves. Set"
+ " @code{fixed-alignment-extra-space} to force staves in"
+ " @code{PianoStaff}s further apart.",