When the Appeals Council decides to review a case, it shall mail a prior notice to all parties at their last known address stating the reasons for the review and the issues to be considered. However, when the Appeals Council plans to issue a decision that is fully favorable to all parties, plans to remand the case for further proceedings, or plans to issue a decision that is favorable in part and remand the remaining issues for further proceedings, it may send the notice of Appeals Council review to all parties with the decision or remand order.