Gaia companion indicators for stars in the RMSTAR catalog are shown. In each case, see the text in Section 4 for rationales for the black line cutoffs adopted. Panel (a) shows log RUWE vs. G magnitude for all RMSTAR primaries, with presumed singles in black and known multiples in red. A horizontal black line is drawn at RUWE = 1.7. Panel (b) shows IPDfmp vs. G magnitude for all RMSTAR primaries, with presumed singles in black and known multiples in red. A horizontal black line is drawn at IPDfmp = 5. Panel (c) shows log RV error vs. G magnitude for all RMSTAR and RKSTAR primaries, with presumed singles in black and known multiples in SB9 (D. Pourbaix et al. 2004) in red, shaded by orbital period. A third-degree polynomial fit (Equation (2)) is shown in black with a ±0.25 log σ_RV envelope in yellow around the best fit line. Panel (d) shows log RUWE vs. log separation in arcseconds for RMSTAR systems with companions detected by Gaia or Hipparcos in pink and companions detected by speckle imaging reported by E. H. Vrijmoet et al. (2022) in green. A horizontal black line is drawn at RUWE = 1.7. Panel (e) shows IPDfmp vs. log separation in arcseconds for RMSTAR systems with companions detected by Gaia or Hipparcos in pink and companions detected by speckle imaging reported by E. H. Vrijmoet et al. (2022) in green. A horizontal black line is drawn at IPDfmp = 5. Panel (f) shows log RV error vs. G magnitude for all RMSTAR primaries, with presumed singles in black and known multiples in red. The polynomial fit is the same as in panel (c).