A contact is a presentity whose presence information is tracked. A contact registers its status, location, and other attributes with the Office Communications Server computer. Contacts can be organized into user-defined groups. In Microsoft UCMA 2.0 Core SDK, contacts and groups are supported only by UserEndpointobjects. The ContactGroupServicesproperty on a UserEndpointinstance provides access to a ContactGroupServicesinstance, which an application can use to add, remove, or update properties of contacts or groups. Contacts can be associated with one or more groups. The ContactGroupServicesclass provides methods to subscribe or unsubscribe as well as to refresh the subscription. To update an instance of a contact or a group, an application supplies an existing contact or group instance to the ContactGroupServicesAPI, modifies the specific fields of interest, and then publishes the new item.

A contact can be identified by its URI, and a group can be identified by its group ID, which is assigned by Office Communications Server when the group is created. An application can use methods on the ContactGroupServicesclass to obtain a contact or group, by using the contact URI or group ID. When an application deletes a group, all of the contacts who belong to the group are updated by the removal of their references to that group.

For more information, see ContactGroupServices.