There are three different types of notifications available in Service Fusion that can be read from the Navigation Bar:
Messages
Rule Notifications
Company Memos
Unread notifications show with bold text and an orange notification dot to the left. Once you click to view more details, the dot will disappear.
If a notification is no longer needed, you can also remove it by selecting the checkbox to the left of the notification and then clicking the Clear button in the bottom right of the panel.
To see past notifications, click the View All button in the bottom left of the panel and that will take you to the full history.