Inter-frequency foreground-cleaned TT power-spectra statistical deviations (in units of standard deviations). Each sub-panel shows differences between the foreground-cleaned cross-spectra, indicated by the row and column labels (row minus column). We show here each spectral comparison over the full multipole range, even though the likelihood discards certain portions of the data. The two lines correspond to the 2015 data and nuisance model (purple) and the 2018 one (orange). In each case, foreground and nuisance cleaning is performed at the spectrum level, as is done in the likelihood, and using the best-fit nuisance parameters from the baseline likelihood for each release (i.e., Planck TT,TE,EE+lowE for 2018). The PTE value quoted in each sub-panel corresponds to the 2018 data (and model) for the full range presented in the plot and with the same Δℓ  =  100 flat binning that is used for the figure.