Direct taxes defined to include listed Acts and any tax the Central Government may notify as direct. The provision defines direct tax by listing specific Acts whose duties or taxes are direct and by adding a residual power for the Central Government to notify any other duty or tax as a direct tax based on its nature or incidence; it also defines Board to mean the Central Board constituted under the Act, with legislative notes recording insertions, omissions, and substitutions that have modified the listed Acts and the Board's designation.