Display notifications

How do the notifications work?

For exemple if a “contributor” submits a blog post for review, noone gets a notification.
If a match is created between two clans and one of them submits a score, the opponents or the admins receive no notificatins.

If a player wants to join a Clan and presses the “join clan” button, the owner of the clan does not receive any notifications.

How does this system work?