further , That the limits set forth in this section may not be exceeded by more than 5 percent for electric or hybrid vehicles purchased for demonstration under the provisions of the Electric and Hybrid Vehicle Research, Development, and Demonstration Act of 1976: Provided further , That the limits set forth in this section may be exceeded by the incremental cost of clean alternative fuels vehicles acquired pursuant to Public Law 101–549 over the cost of comparable conventionally fueled vehicles: Provided further , That the limits set forth in this section shall not apply to any vehicle that is a commercial item and which operates on alternative fuel, including but not limited to electric, plug-in hybrid electric, and hydrogen fuel cell vehicles. 703. Appropriations of the executive departments and independent establishments for the current fiscal year available for expenses of travel, or for the expenses of the activity concerned, are hereby made available for quarters allowances and cost-of-living allowances, in accordance with 5 U.S.C. 5922–5924 . 704. Unless otherwise specified in law during the current fiscal year, no part of any appropriation contained in this or any other Act shall be used to pay the compensation of any officer or employee of the Government of the United States (including any agency the majority of the stock of which is owned by the Government of the United States) whose post of duty is in the continental United States unless such person: (1) is a citizen of the United States