Section 4
SEC. 4. Section 3 is hereby amended to read as follows: "SEC. 3. Persons travelling on non-revenue tickets shall, unless otherwise exempted herein, pay the travel tax provided for under Section One hereof based on the classification of their non-revenue tickets, except officials of travel operators, airline and shipping companies travelling on official company business: "Provided, however, That for the purposes of exemption, discounted tickets and tickets with service fees shall not be considered non-revenue tickets."