Examples of SEDs from our database for different types of YSOs From top to bottom: a Class 0, a Class I, a Flat-Spectrum, a Class II. a Class III, and a Herbig AeBe star. See YSO classes discussion in Sect. 3.3. Photometric data collated by us is plotted in coloured symbols, while data points retrieved by processing data from the VizieR-SED tool are plotted contoured in black. The grey area shows the wavelength range used for deriving α_IR indices in Sect. 3.3.