Comparison plots of astrometric parameters for each multiple in RMSTAR. Parallax, proper motion in R.A., and proper motion in decl., respectively, are plotted for each system, with primary stars’ values on the x-axis and the companions’ values on the y-axis. For stars with more than one companion, a primary star’s parameters are plotted against each companion. Points are colored by the larger error of each pair for each parameter. Solid black one-to-one lines are drawn on each plot. The dashed lines in the residual plots are drawn at ±2 mas for parallax (panel (a)) and ±30 mas yr⁻¹ for proper motions (panels (b) and (c)); these are thresholds for automatic inclusion of companions to RMSTAR. Companions beyond these cutoffs have been verified as physical using additional information (see Section 3.2 for more details).