Selection is nothing more than an alternative to explicit bond order encoding. No other properties whatsoever are conferred to selected atoms. The members of a DS may be assigned the labels "aromatic," "antiaromatic," "non-aromatic," or any number of other designations by downstream applications. Two encodings differing only in the presence of a DS should be considered equivalent. Balsa imposes no rules around whether or not a selectable atom must be selected, although users may do so voluntarily.