"Automatic" means if NorthStar does not succeed in collecting NSF checks in its first phase process, they will move any uncollected checks PLUS all stop payment checks to their most aggressive collection tactics "automatically" (NorthStar will do this for you).

"Selective" means NorthStar will not engage in second phase collection efforts unless you go to their web site and manually select these checks for collection

A nice summation of how NorthStar process checks is located here.