DIFF Subgroup
E02D 29/0258 Full Title
underground or underwater structures (underground tanks B65D88/76; hydraulic engineering, e.g. sealings or joints, E02B; underground garages E04H6/00; underground air-raid shelters E04H9/12; burial vaults E04H13/00); Retaining walls > Retaining or protecting walls (piers or quay walls E02B3/06)
Of 4 combined children, 0 exist in both systems.
4 codes are CPC-only extensions.