From the "Notification Programming Guide for Websites"[1]:

    > Opting In to Notifications
    > 
    > Users must opt in to receive notifications. The opt-in process only occurs
    > once per domain. The presentation of asking for permission is identical
    > for all website notifications. In fact, the permission policy that
    > a user chooses for push notifications applies to local notifications.

It goes on to say that "users can adjust their notification preferences in Safari preferences and System Preferences".

[1]: https://developer.apple.com/library/mac/documentation/Networ...