Commission 42 (C42) co-organized, together with Commission 27 (C27) and Division V (Div V) as a whole, a full day of science and business sessions that were held on 24 August 2012. The program included time slots for discussion of business matters related to Div V, C27 and C42, and two sessions of 2 hours each devoted to science talks of interest to both C42 and C27. In addition, we had a joint session between Div IV and Div V motivated by the proposal to reformulate the division structure of the IAU and the possible merger of the two divisions into a new Div G. The current report gives an account of the matters discussed during the business session of C42.