Illustration of divergent one- and two-point correlation corrections from organised randoms. Left: pixel (one-point) correlations between the galaxy number density N_gal/N_rand in biased (according to the 800C SOM) FLASK mocks and the mean PCA components in the same pixels (see Appendix B). Correlations normalised by uniform randoms’ counts-in-pixels are given in blue, and those normalised (corrected) by the pixel counts of 100A organised randoms are given in orange. Correlations and errors are the mean and the root-diagonal of the covariance over 30 FLASK realisations, respectively. Purple shading indicates the expected intrinsic 1σ spread in these correlations, as calculated over 100 unbiased FLASK realisations (Fig. B.1). Shown here are the 4 (out of 14) correlations for which the organised randoms correction most improves consistency with unity. Right: corresponding biased and recovered two-point angular clustering correlations w(ϑ), shown in ratio to (top) and overlaid on (bottom) the unbiased clustering signature, as in Fig. 9. We also show the cross-correlation between organised randoms and the unbiased data and its ratio to the unbiased clustering signal in orange. Correlations and errors are again the mean and the root-diagonal of the covariance over 30 FLASK realisations.