Multiple Appearance Directory Numbers (MADN) If your phone line is in a Multiple Appearance Directory Number group then there will be an entry in the Group Membership section for it called Sim-Ring Group: name. Click on this entry to view that Sim-Ring Group: The following information is shown on the right hand panel of the screen: What department this Sim-Ring Group is in, if any. If your business does not use departments then this will say None. How many lines are in the group. The lines which are in this group. Your line will be in this list. Only an administrator can make changes to a Sim-Ring Group.