(side-relative-direction ,ly:dir? "Multiply direction of
@code{direction-source} with this to get the direction of this
object.")
+ (simple-Y ,boolean? "Should the Y placement of a spanner
+disregard changes in system heights?")
(size ,number? "Size of object, relative to standard size.")
(skyline-horizontal-padding ,number? "For determining the
vertical distance between two staves, it is possible to have a