It doesn't.
My [networks] section looks like this:
[networks]
n0=Quakenet
n1=EFnet
n2=Undernet
n3=IRCnet
n4=Gamesnet
n5=DALnet
There's also a [success] section which does what you're talking about:
[success]
n0=irc.freenode.net,3
n1=kernel.dal.net,1
n2=irc.efnet.info,1
n3=eu.undernet.org,1
n4=irc.23-net.org,1
