Astrometric signature α_UEVA calculated from either AEN (top) or ruwe (bottom) and compared to the quantities in the 5p (blue dots) and 6p (orange dots) datasets. The dashed black line shows, respectively, the α_UEVA=AEN and α_UEVA=0.2 ruwe relationships mentioned in the text, through Eqs. (23), (24) and (27). The red and green vertical lines show, respectively, the AEN=2 mas and ruwe=1.4 thresholds.