Configuration of the analysed multiple systems. Left: considering only the data catalogued in MSC. Right: including the results of this study. a) WDS 08079–6837; b) WDS 08314–3904; c) WDS 10209–5603; d) WDS 13226–6059; e) WDS 15185–4753; and f) WDS 20118–6337. Stellar components are represented by circles. Filled circles are stars observed in the present paper. No symbol is plotted for stellar components that are not visible in the spectrum (secondaries of SB1 systems). Dashed lines divide approximately the period axis in spectroscopic (S), visual (V), and common proper-motion (C) ranges. Dotted lines indicate a doubtful physical link between the components. The size of the circles roughly scale with the stellar mass. Green thick lines mark separation intervals that have not been investigated and might harbour additional hierarchical levels.