Comparison of the core ERQ UV line ratios with N-loud quasars (Batra & Baldwin 2014) and the median ratios of SDSS QSO2 at z >  2 (Group 1: CIV/HeII < 4 and Group 2: CIV/HeII > 4, Silva et al. 2020). HeIIλ1640 is not detected for most core ERQ, therefore lower limits are shown with arrows for the ratios involving this line. The minimum and maximum y- and x-axis values have been selected in all diagrams to span approximately the full range of values shown by most plotted objects. The core ERQ line ratios (measured and lower or upper limits) partially overlap the area of the diagrams covered by N-loud quasars.