Residuals for each cross-spectrum entering into the TT high-ℓ likelihood. The blue points show the residuals compared to the baseline ΛCDM model for the 2018 release, while the grey points show the 2015 residuals (compared to their own best-fit model). The green lines show the foreground-corrected co-added CMB spectra, computed using the multipole cuts described in Table 13, i.e., excluding the shaded regions in each panel, while the pink lines are the conditional prediction, obtained from all of the other spectra that enter the likelihood. The blue lines show the ±1 σ and ±2 σ contours corresponding to the diagonals of the blocks of the 2018 covariance matrix appropriate to the cross-spectrum shown. Orange and red points correspond to 2 and 3 σ outliers. PTEs are computed for the non-shaded regions.