This Decision establishes the Executive Bylaws, specifically covering Articles 1 to 48, which govern tax administration and compliance. Its primary purpose is to provide detailed regulations for implementing the governing tax law. A key focus, as detailed in Article 10, is defining the taxable year. The bylaws stipulate that tax is assessed annually on taxable income, with the first fiscal period for a tax declaration being a standard 12-month calendar year. It provides flexibility, allowing a taxpayer to adopt a different accounting period of up to 18 months, subject to prior approval from the Tax Administration.