Percentage of observer-dependent (OD) CGs for four different sub-samples defined by varying the maximum surface brightness or the velocity gap in the line of sight. The left column shows the number of CGs (top panel), the percentages of CGs that are lost due to the velocity filter (middle panel), and μ criterion (bottom panel) as a function of the original μ_max of the CG, i.e. each bin only takes into account CGs with an original μ less than the corresponding bin value (μ ≤ μ_max). The right column shows the same as the left column, but for samples selected as a function of the maximum velocity difference of galaxy members from the CG centre (ΔV ≤ ΔV_max). In each case, the last bin corresponds to the original values of μ_lim and ΔV_lim of the CG sample.