Private Contact: Not visible in Contact list, Will not appear in Call Log History.
User can configure the contact as private and those contacts will not be appeared in contact list and Call logs history. Please don't misuse of this feature as it can be used to destroy the criminal activity as well.
Contact configured as private cannot be synced with other targeted device as it is private and device has not direct access to it. It can be synced with password.
There is an android application available in Google Play which will give you the similar kind of functionality.
Actually, in this app you can configure some of your contact for auto deletion. It means the same. Once you call them, it will automatically delete name & contact number of the person to whom dialed.
If you want to delete the call logs automatically for some your contacts then look at belwo demo for Call Log Filter application.