title: Google calendar API notification
body: <p>I'm making a web application which uses the Google calendar API. People can create events and see them in the application. When an user changes an event all the attendees of that event get an email about the change. For sending the email I use:</p>
  
  <pre><code>EventsResource.UpdateRequest updateRequest = new EventsResource.UpdateRequest(service, eventToUpdate, CalendarId, eventToUpdate.Id)
  {
      SendNotifications = true,
  };
  </code></pre>
  
  <p>Now Google calendar monitors the event and when something changes a notification is send. But I can never find any documentation about when the notification is triggered. For as far as I now an email is send when the user changes the following: Summary and description. </p>
  
  <p>Does anybody know all the elements that trigger the notification?</p>