If nick is given as parameter, the ban type is used to generate the ban mask. /SET ban_type specified the default ban type. Ban type is one of the following:
Normal - *!*user@*.domain.net
User - *!*user@*
Host - *!*@host.domain.net
Domain - *!*@*.domain.net
Custom [nick] [user] [host] [domain]
Examples:
/BAN looser - Bans the nick 'looser'
/BAN -host looser - Bans the host of nick 'looser'
/BAN *!*@*.org - Bans all the users coming from any .org domain.
/SET ban_type custom nick domain - nick!*@*.domain.net
/SET ban_type custom user host - *!user@host.domain.net