Left panel: cross-correlation function of the R-band magnitudes with the total C IV BAL EW tracing the continuum. Right panel: cross-correlation function of the R-band magnitudes with the total C IV “red” NAL EW. In both panels, both the ICCF (black solid line) with 1σ errors in the y direction (grey bars), and ZDCF computed with 15 points per bin (black points) with 1σ errors in both x and y directions, are shown. The dashed vertical lines indicate the delays of the most prominent peaks enclosed by their uncertainties at 68% probability (dotted lines), which are also numerically reported.