+ SERVER <servername> <info>
+ SERVER <servername> <hopcount> <info>
+ SERVER <servername> <hopcount> <token> <info>
+ .
+ The first form registers the local connection as a new server in the
+ network, the second (RFC 1459) and third (RFC 2812) form announce a
+ new remote server in the network.
+ .
+ The SERVER command is allowed on unregistered or server-links only.
+
+ References:
+ - RFC 1459, 4.1.4 "Server message"
+ - RFC 2813, 4.1.2 "Server message"