Format is 900 <nick> <nick>!<ident>@<host> <account> :You are now logged in as <user>
Format is 901 <nick> <nick>!<ident>@<host> :You are now logged out
SASL numerics that don't have any parsable information.
RPL_SASLMECHS. This is sent in response to a request for a mechanism the server does not support, and will list any mechanisms that are available.