ContactSubscription class
Lync 2013
Specifies the type of contact information to be to be subscribed on a collection of contacts set in the subscription.
Namespace: Microsoft.Lync.Model
Assembly: Microsoft.Lync.Model (in Microsoft.Lync.Model.dll)
You must cache a ContactSubscription that you create to maintain subscriptions to contacts you get using the search feature, call into GetContactByUri, or other methods that return Contact instances that are not in the Lync client contact list. You continue to receive contact information updates for the contacts in the cached ContactSubscription until you either un-subscribe to the contacts or destroy the ContactSubscription. The ContactSubscription is cached as a class member.