yesterday i ask about some sub addr on monero
now after i read more about it
i find something like "on monero booth party is encrypted so no one know until you given the watch key for SINGLE transaction"
the question is

example
if i had addr then i send it to any of my client
then does i will be able to know the client address like... the john send 10$ via monero
can i know his addr? or just notification that i received 10$ ?