\overrideProperty "Score.NonMusicalPaperColumn" parameters...

[Widget]

Kind people,
    I'm trying to work out what the following does:
        twoVerses = { \overrideProperty "Score.NonMusicalPaperColumn"
            #'line-break-system-details
            #'((alignment-offsets . (0 -5.5 -7.5 -13 -18.5 -20.5 -26 -31.5 -33.5 -39 -44.5 -46.5 -52 -56.5 -61)))
        }

    In particular, how does the alignment-offsets parameter work and what do the numbers mean/do?
    Many thanks,
    Widget