We see in psochim 4a Rav went from (a city in) Babylon (why does rashi have to go to such lengths to say it was a city there?) to visit his 'double' uncle R Chiya. When he got there R Chiya asked him either about rav's parents or his own parents (rav's grandparents) if they were alive.

Rav did not answer him directly because one must not tell someone that someone has died. If one can write, it would seem also not, otherwise Rav would have written.

(The minag according to shulchan oruch is to pour out water. How the minhag today works where a car goes round with a loudspeaker or notices hung up is discussed.)

So for those learning the daf yomi. Exactly whom did he ask about, whose father, whose mother and whom did Rav reply about.