For activities, the unique identifier for the item to which the activity is related, but not linked.
Mac Catalyst 13.0+Beta
Unlike the similar relatedUniqueIdentifier property, this property does not link the lifetime of the item to the lifetime of the activity. In particular, deleting the item does not delete the activity.
An identifier that represents the domain or owner of the item.
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.