code: def record_make_all_subfields_volatile(rec):
      
      for tag in rec.keys():
          for field_position, field in enumerate(rec[tag]):
              for subfield_position, subfield in enumerate(field[0]):
                  if subfield[1][:9] != "VOLATILE:":
                      record_modify_subfield(rec, tag, subfield[0], "VOLATILE:" + subfield[1],
                          subfield_position, field_position_local=field_position)
docs: Turns all subfields to volatile