Spectral models (in νF_ν representation) tested in this work. From top to bottom: a Band function with a high-energy exponential cutoff (Bandcut, green), a Cutoff power-law model (CPL, orange), a Band function (Band, blue) and a single power-law model (PL, red). The Band model can describe two different cases: either both spectral indices are larger than −2, or the second one is smaller than −2. In all models, we use the letter α for spectral segments where the νF_ν flux increases with energy (and distinguish between α₁ and α₂ in case two increasing segments, separated by a spectral break, are present), and β to refer to a decreasing spectral segment. The number within brackets next to the model name refers to the percentage of cases for which each model provides the best fit to the data.