Spectrum of SN 2006oz (red) obtained at the NOT. For comparison we show 3 spectra from Quimby et al. (2011) at similar pre-maximum phases. The colored spectra are smoothed versions (moving average of 5 pixels) of the original gray spectra. All spectra were plotted in their rest frame assuming z = 0.376 for SN 2006oz. The inset shows a zoom of the area around 2800 Å. At this redshift we identified the only probable line (although at low significance 2.7σ) consistent with the Mg ii doublet (which would appear blended at this resolution).