title: Cross-calendar integration (Google Calendar & Outlook Calendar)
body: <p>I'm working with Google Calendar(GC) and Outlook Calendar(OC) APIs.</p>
  
  <p>Let's say a GC user invites an OC user to an event created in GC. When creating a new event in the OC user's calendar, the OC API creates a <em>new</em> event ID instead of using the existing GC event's ID. What this means is that there's no unique identifier for the two events and they might as well be different events. My application needs to connect the two events.</p>
  
  <p>Currently the OC calendar API says the Id field is not writable. The GC API allows a writable event id but not for cross-calendar invites (since the event creation is happening inside the guts, is not directly called by my app).</p>
  
  <p>Any ideas / suggestions? Many thanks!</p>