A brief history is given of the CCIR with its Study Group structure, in particular Study Group 6 on Ionospheric Propagation. The system of documentation is described with special reference to the Reports which form a most valuable source of information on ionospheric propagation in relation to radio communication. The nine Working Groups under which the work of Study Group 6 is organized at the Interim and Final Meetings are considered in turn, and reference is made to the cooperation with URSI in the more scientific aspects of the work. The part played by the CCIR as a subsidiary body of the ITU is explained in providing the basic information required by the IFRB and the planning experts at ITU Conferences.