> If a user wants the symbol to be positioned at an absolute offset
> from its Y-parent, they can just set outside-staff-position to () in
> addition to setting Y-offset.
Unfortunately, I can't `just set outside-staff-position' because this
property doesn't exist yet -- at least I wasn't able to find it.
However, this is the missing info -- as soon as the skyline stuff gets
documented (and implemented :-) properly, this very feature should be
described also.
Sorry, outside-staff-priority, not outside-staff-position.