code: def _write_families(fm_group, tags):
      
      for set_id, name in tags.items():
          family = fm_group.create_group(_family_name(set_id, name))
          family.attrs.create("NUM", set_id)
          group = family.create_group("GRO")
          group.attrs.create("NBR", len(name))  # number of subsets
          dataset = group.create_dataset("NOM", (len(name),), dtype="80int8")
          for i in range(len(name)):
              name_80 = name[i] + "\x00" * (80 - len(name[i]))  # make name 80 characters
              dataset[i] = [ord(x) for x in name_80]
docs: Write point/cell tag information under FAS/[mesh_name]