nonstaff-relatedstaff-spacing: nedds some precision

[Jean-Charles Malahieude]

Hi all,

In spacing.itely (paragraph beginning on line 2127) I read this sentence:

"This means that the placement of a non-staff line depends
on both the surrounding staves and the surrounding non-staff lines.
Setting the @code{stretchability} of one of these types of spacing to
a small value will make that spacing dominate.  Setting the
@code{stretchability} to a large value will make that spacing have
little effect."

It is not clear to me _which_ spacing will dominate or have little 
effect: does it concern the very non-staff line I'm manipulating, or one 
of the "other types" where stretchability has been adapted?

TIA,
Jean-Charles