There are 3 types of "Privilege", well 4 really. Owner, Friend, Anonymous, and Closed.
In all cases before a call can be initiated a set of rules MUST be met.
Owner: That's you (the owner of the telephone) and of course anybody you give that privilege to. There are no rules for owners and the time limit is set to 24 hours, because "Hey! It's your phone... your rules!". People with this privilege can access the system at anytime and dial any number WITHOUT restriction. This is exactly as you would expect since it's your telephone.
Friend: Friends must use the friends rules tables that you have assigned. With this you can restrict access times and time limits as well as what phone numbers you decide are safe.
Closed: Closed is what it sounds. This is in case you wish to maintain the record but not allow access to that user.