O VII (RGS1) and N VI (RGS2) He-like multiplets in RR Tel. The spectra have been binned to a minimum of three counts per bin. The red line shows the best-fit model for the resonance and forbidden lines. The intercombination line is shown with its intensity set to the upper obtained from the fit. Dips due to bad columns are clearly seen near 21.6 and 21.8 Å. The blue line in the top panel shows the analytical representation of the three Gaussians, broadened with the instrumental width (≈0.07 Å FWHM) and having the intensities derived in the fit.