Instance Property


The identifier of the category object that represents the notification's type.


iOS, Mac Catalyst, watchOS
@property(copy, nonatomic) NSString *categoryIdentifier;
@property(copy, atomic) NSString *categoryIdentifier;


Use notification types to distinguish between the different types of notifications your app supports. You use this support primarily to create actionable notifications—that is, notifications with custom action buttons—and to redirect your notifications through either your notification service app extension or your notification content app extension.

Assign a value to this property that matches the identifier property of one of the UNNotificationCategory objects you previously registered with your app. If you assign a string that does not match one of your registered categories, the system displays your notification without custom actions and without routing it through your app extensions.

See Also

Identifying the Content


An identifier that you use to group related notifications together.