A scripted ban list is often referred to as a shitlist if you want to search for one that is already made. It stores the bans in a file or wherever else and when someone banned joins the room, they will be kick/banned and the ban will be automatically removed after a period of time. This does not prevent someone from joining the channel, but does prevent them from talking or remaining in the channel. Such a ban list can be very large (up to the size of the drive you're storing it on).
Still, as Watchdog said, if you're moving to another network, the chances of needing a large ban list are minimal unless you're advertising it to anyone who is harassing you now.
