The ID of the record zone to monitor.
- iOS 8.0–10.0Deprecated
- macOS 10.10–10.12Deprecated
- Mac Catalyst 13.0–13.0Deprecated
- tvOS 9.0–10.0Deprecated
The value of this property applies both to query-based subscriptions and zone-based subscriptions. Specifying a record zone limits the search scope to the records in that zone. In the case of a zone-based subscription, the search encompasses all records in the zone. For a query-based subscription, the search encompasses only records of a specific type in that zone.
For zone-based subscriptions, the value of this property is set automatically by the
init(zone methods. For all other subscription types, the default value is
nil. To apply a zone to a query-based subscriptions, you must assign a value explicitly.