

There is warn, kick, ban, and unban, all taking a required player argument and an optional reason (except for unban which doesn't need a reason).
When a player is kicked or banned, they will be killed just before being kicked or banned, to fix an issue where they could continue to effect the game afterwards for a bit of time.
With PersistentData, when a player is banned, their ban reason will be saved to their client data file, and they'll remain permanently banned from your future lobbies unless you unban them.