DIFF Subgroup
E04H 12/2253 Full Title
Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures (cooling towers E04H5/12; derricks for oil drilling E21B15/00) > Sockets or holders for poles or posts
Of 3 combined children, 0 exist in both systems.
3 codes are CPC-only extensions.