Traditionally, Chapter VI of the Transactions B Volume contains the Reports by the IAU Commissions. However the old Commissions ceased to exist at the XXIX General Assembly and were replaced by the new ones (see the Preface). To mark this important milestone in the history of the IAU, it was decided to dedicate the Volume XXIXA of the Transactions A of the IAU to the Reports by the old Commissions. The Volume, edited by Thierry Montmerle, is entitled “Commissions legacy Reports”: because of this, the Chapter VI of the current Transactions B Volume has been left empty, but it was kept as a chapter not alter the traditional order.