The federal income tax enacted in 1913 included corporate and individual income taxes. It defined income using language from prior laws, incorporated in the Sixteenth Amendment, as "all income from whatever source derived". The tax allowed deductions for business expenses, but few non-business deductions. In 1918 the income tax law was expanded to include a foreign tax credit and more comprehensive definitions of income and deduction items. Various aspects of the present system of definitions were expanded through 1926, when U.S. law was organized as the United States Code. Income, estate, gift, and excise tax provisions, plus provisions relating to tax returns and enforcement, were codified as Title 26, also known as the Internal Revenue Code. This was reorganized and somewhat expanded in 1954, and remains in the same general form.