ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. 1,2,4,5-tetrachlorobenzene 1,2,4,5-tetrachlorobenzene (C6H2Cl4) Originally from the CUAHSI HIS VariableNameCV. See: http://his.cuahsi.org/mastercvreg/edit_cv11.aspx?tbl=VariableNameCV.