Other referential objects: charge,ref_choice-method,
ref_checkbox-class,
ref_choice-class,
ref_coe-class, ref_dc-class,
ref_df-class, ref_list-class,
ref_par-class,
ref_parqual-class,
ref_parquan-class,
ref_period-class,
ref_stage-class,
ref_taxa-class,
ref_year-class