Comparison between total spectrum and our single-region spectral fitting procedures around the [NII]λ5756 (upper panels), [SIII]λ6312 (middle panels) and [OII]λλ7320, 7330 (lower panels) auroral lines for regions 268 (left column) and 817 (right column) in NGC5068, the same from Fig. 2. When using single-region spectral fitting, the RMS of residuals between data and best-fit around the [NII]λ5756, [SIII]λ6312, and [OII]λλ7320, 7330 lines is respectively of 464, 2781, and 3692 for region 268 and 122, 174, and 420 for region 817. When using total spectrum fitting procedure (golden fits), the RMS of residuals reaches values of 611, 3073 and 3798 for region 268 and 169, 253 and 460 for region 817. The corrected spectral error is represented as a shaded region in the residuals panels.