This Decision establishes the Executive Bylaws, comprising Articles 1 to 48, governing tax procedures. Its primary purpose is to regulate the methods of tax assessment and the associated administrative processes. The Bylaws stipulate that tax is assessed based on the taxable net income declared by the taxpayer in the Tax Declaration. However, it grants the Tax Administration significant authority to review, rectify, or modify these declarations if deemed necessary. In cases where a declaration is not accepted, the Administration is empowered to disregard it and determine the taxable income by estimation, as further detailed in Article 19.