(1) "??? ": If a line begins with three question marks and a space, the rest of the
line defines the start of expected output from the server. If what is
received does not match, the client bombs out with an error message.
+ Escape sequences described below in (7) are usable in the expected text.
(2) "???*": If a line begins with three question marks and an asterisk, the server
is expected to close the connection.