Company events
New Event: you've been invited to an event.
Event reminder: before the event and again the day before. People who declined don't get reminders.
Event cancelled.
Surveys
New Survey: your company would like your opinion. You get this when a survey you're in opens and you haven't answered it yet. Admins choose whether a survey sends a notification when they publish it.
See How notifications work in All Gravy to pause or schedule notifications.