The Active Directory set of defined objects represents the minimum set of Active Directory objects that should be implemented by an Active Directory provider writer. Providers writers are encouraged to document and provide implementations for namespace-specific Active Directory objects.
An Active Directory object that is defined by Active Directory might have additional functionality in a particular namespace that is not exposed by the Active Directory definition of the object. A provider could then implement a namespace-specific interface on the object to expose such functionality. Clients would discover the interface by browsing the type library..
For example, the PrintQueue component in namespace X might expose a Statistics interface,IADsPrintQueueStatistics, which includes the read-only properties TotalJobsServiced and AverageServiceTime. In order to retrieve the interface from a PrintQueue, the client would use the standard COM QueryInterface method..
Also, a namespace might expose an Active Directory object that is not defined by Active Directory at all. A provider could implement a new Active Directory object and it would be discoverable using the schema management objects.
For example, namespace X might also include a FaxQueue component object. A provider writer for namespace X could write the complete implementation of this object, including the IADsFaxQueue interface and all the properties and methods needed to store FaxQueues in the DS.