The formats of an ircII server list is as follows:
  servername
  servername:portnum
  servername:portnum:password:nick
  servername::password:nick
The servername is the name of the server, the portnum is the port
number of that server to connect to, and the password is a
connection password for that server.  The first format above
uses the default port number and no password.  The second format
specifies a port number for connection to the specified server
and no password.  The third format specifies both a port number
and password for connection.  The final format uses a password
and the default port number.

And, since we call these "server lists", you may specify as many
of the above formats as you wish.  These may be used on the IRCII
command line (See HELP ircII command_line_args) and in the
IRCSERVER environment variable (see HELP ircII environment_vars).
