Gaia DR3 statistical indicators of very close multiplicity. Top : astrometric_excess_noise (ϵ) vs RUWE. Middle : σ(V_r) vs G. Bottom: ipd_gof_harmonic_amplitude vs RUWE. In all panels, pink and blue open circles are for stars that were considered single and part of multiple systems, respectively, and the red thick dashed lines indicate the corresponding close binary selection criterion in Table 3.