If you unsubscribe from a friend on facebook then resubscribe, will they know?

[jny]

I think if you unsubscribe a friend, they do not get a notification so they won't know. But if you subscribe to their updates again later on, will they get some sort of notification telling them that?

Also, if you delete a friend from facebook, will all the previous wall posts you put on their wall disappear too?

[?]

yes

[PC]

As far as I know they will get a notification once you resubscribe but if you dont bother resubscribing they will not know at all.