Classification of Portland Cement: slag and pozzolana cements treated as Portland Cement, attracting the same excise rate. Portland Slag Cement and Portland Pozzolana Cement merit classification as Portland Cement under sub-heading 2502.29 during the material period; they are not to be treated under Heading 2502.90. The Board concluded the tariff's generic entry for Portland Cement was intended to include these varieties, and directed trade and field formations to finalise pending disputes and assessments accordingly.