[O III] emission line properties for the luminosity-and-redshift-matched red and control QSO samples from the entire SDSS survey. Upper panel: comparison of all red and control QSOs with [O III] line measurements with F_peak > 10 × rms_{5100 Å}. It is important to note the number of red QSOs satisfying the condition is ∼50% larger than the control QSOs. This is shown more clearly in the lower panel, where the distribution of signal-to-noise ratio of the wing emission-line component, defined as = F_peak(wing)/rms_{5100 Å}, is shown for red and control QSOs. While here the only condition for a source to be included was to have [O III] detections, the number of red QSOs satisfying this condition is 5 times larger than that of the control sample.