- * in the format "[<port>][:<ip>]". <port> may be omitted if 'default_port' is
- * nonzero, in which case it defaults to 'default_port'. If <ip> is omitted it
- * defaults to the wildcard IP address.
+ * in the format "[<port>][:<ip>]":
+ *
+ * - If 'default_port' is -1, then <port> is required. Otherwise, if
+ * <port> is omitted, then 'default_port' is used instead.
+ *
+ * - If <port> (or 'default_port', if used) is 0, then no port is bound
+ * and the TCP/IP stack will select a port.
+ *
+ * - If <ip> is omitted then the IP address is wildcarded.