One relay (HSDir) knows that someone (but not who) wanted to look up the record for where to leave a message to request to talk to "X".

Another relay (Introduction Point) knows that someone (but not who) left a message asking to talk to "Y" (see note.) at some location that it doesn't know.

(Note: "Y" is not the same as "X", it is actually a distinct key that it published for each Introduction Point in the Hidden Service descriptor. If the Introduction Point has a descriptor for "X", it knows "Y" is "X" and therefor it is serving "X", otherwise it knows nothing about either party.)

Yet another relay (Rendezvous Point) know that someone (but not who) is talking to some hidden service (but not which).

No single relay knows with certainty that they ever did talk or who either of the participants were nor what they spoke about.

(Assuming the URL is http://X.onion?foo=bar)

One relay (HSDir) knows that someone (but not who) wanted to look up the record for where to leave a message to request to talk to "X".

Another relay (Introduction Point) knows that someone (but not who) left a message asking to talk to "Y" (see note.) at some location that it doesn't know.

(Note: "Y" is not the same as "X", it is actually a distinct key that it published for each Introduction Point in the Hidden Service descriptor. If the Introduction Point has a descriptor for "X", it knows "Y" is "X" and therefor it is serving "X", otherwise it knows nothing about either party.)

Yet another relay (Rendezvous Point) know that someone (but not who) is talking to some hidden service (but not which).

No single relay knows with certainty that they ever did talk or who either of the participants were nor what they spoke about.

At most the value of "X" is known by some HSDir(s).

One relay (HSDir) knows that someone (but not who) wanted to look up the record for where to leave a message to request to talk to "hiddenservxxxxxx".

Another relay (Introduction Point) knows that someone (but not who) left a message asking to talk to "hiddenservxxxxxx" at some location that it doesn't know.

Yet another relay (Rendezvous Point) know that someone (but not who) is talking to some hidden service (but not which).

No single relay knows with certainty that they ever did talk or who either of the participants were nor what they spoke about.

One relay (HSDir) knows that someone (but not who) wanted to look up the record for where to leave a message to request to talk to "X".

Another relay (Introduction Point) knows that someone (but not who) left a message asking to talk to "Y" (see note.) at some location that it doesn't know.

(Note: "Y" is not the same as "X", it is actually a distinct key that it published for each Introduction Point in the Hidden Service descriptor. If the Introduction Point has a descriptor for "X", it knows "Y" is "X" and therefor it is serving "X", otherwise it knows nothing about either party.)

Yet another relay (Rendezvous Point) know that someone (but not who) is talking to some hidden service (but not which).

No single relay knows with certainty that they ever did talk or who either of the participants were nor what they spoke about.