; and of which $244,000,000, to remain available for obligation until September 30, 2021, shall be for research, development, test and evaluation: Provided , That such amount is designated by the Congress as being for an emergency requirement pursuant to section 251(b)(2)(A)(i) of the Balanced Budget and Emergency Deficit Control Act of 1985. General Provisions—This Title 10301. Notwithstanding any other provision of law, funds made available under each heading in this title shall only be used for the purposes specifically described under that heading. 10302. Upon the determination of the Secretary of Defense that such action is necessary in the national interest, the Secretary may transfer up to $500,000,000 between the appropriations or funds made available to the Department of Defense for expenses relating to the use of the National Guard in response to coronavirus: Provided , That such funds may only be transferred among military personnel and operation and maintenance accounts for the National Guard provided for in this title: Provided further, That the Secretary shall notify the Congress promptly of each transfer made pursuant to the authority in this section: Provided further , That the authority provided in this section is in addition to any other transfer authority available to the Department of Defense and is subject to the same terms and conditions as the authority provided in section 8005 of the Department of Defense Appropriations Act, 2020: Provided further , That the transfer authority in sections 8005 and 9002 of the Department of Defense Appropriations Act, 2020, shall not apply to amounts appropriated or otherwise made available in this title. 10303. Notwithstanding section 2208(l)(3) of title 10, United States Code, during fiscal year 2020, the amount of advance billings rendered or imposed by Defense working capital funds may exceed $1,000,000,000. In the preceding sentence, the term ‘‘advance billing’’ has the meaning given the term in section 2208(l)(4) of such title. IV Energy and Water