Comparison of information criteria scores computed for the rest-frame hardness-duration distributions of 155 GRBs from the ‘GBM all’ sample. The durations were computed in the observer- and rest-frame energy windows 100 − 900 keV, which in the latter case corresponds to the $\frac{100}{1+z}-\frac{900}{1+z}$ keV instrumental bandpass. In both cases, the durations were corrected for the cosmological time dilation. The following designations are introduced for the models: 𝒩 (𝒮𝒩) and 𝒯 (𝒮𝒯) denote the symmetric (skewed) Gaussian and Student distributions, correspondingly; the number to the left of the model provides the amount of clusters; and the number in parentheses gives the amount of free parameters of the model. The red filled area corresponds to the Δ_IC < 2 area, while the blue filled area marks the 2 < Δ_IC < 4 area.