When you make a contact a favorite, you can easily dial the contact by tapping the gray silhouette icon next to the contact's name. Each favorite contact is assigned an index number, which determines the order they appear in your favorites list. Favorite contacts with low index numbers display on your phone below your private lines, based on the number of keys available on your phone's model.
To designate a contact as a favorite:
The phone now shows your contact as a designated favorite identified with a gray silhouette.