Nine research teams organized a round-robin measurement campaign of the wake of two porous discs in a homogeneous and "low-turbulent' flow. Mean streamwise velocity and turbulence intensity profiles at four diameters downstream of the discs were measured and compared through such metrics as the maximum of velocity deficit, the maximum of turbulence intensity, the wake width and the thrust coefficient. The dependence of these metrics on the inflow conditions (freestream turbulence intensity and Reynolds number based on the disc diameter) is discussed.