Add check box to make a group a Broadcast only group.  Example if you have a group called "Code Stroke"  for this group you want to broadcast notifications out to them.  A physicialn may tell a nurse to "call a code stroke" on a patient.  The nurse then gives the command "call code stroke"  instead of "Urgent broadcast code stroke". One person recieves the notice instead of the group of staff assinged to respond. 
I would like to see a check box added like the "permisions only (not callable)" box.  This would ensure if someone says call instead of urgrent broadcast to the groups with the check, it will know to translate into urgent broadcast for the groups that are set as broadcast only.