title: Sharepoint 2010 Calendar Event Receiver
body: <p>I have been tasked with creating a calendar in a root site that get's updated from child site calendar events.</p>
  
  <p>I am able to access the Calendar List from the parent site in the child site's to add an event.  However, I'm having trouble finding a way to create a uniqueIdentifier for the event so that when the child calendar's event is updated or deleted, the parent site calendar get's updated as well.</p>
  
  <p>The ListItem ID field appears to be only unique among the site.  I did find a UniqueItemId field, but apparantly it's read-only in the SP LIstitem object.</p>
  
  <p>Can someone please give me some guidance here?</p>
  
  <p>Many thanks!</p>