D.C. Code § 47-1810.03
In any of 2 or more organizations, trades, or businesses (whether or not incorporated, whether or not organized in the District, and whether or not affiliated) owned or controlled directly or indirectly by the same interests, the Mayor is authorized to distribute, apportion, or allocate gross income or deductions between or among such organizations, trades, or businesses, whenever in his opinion such distribution, apportionment, or allocation is necessary in order to prevent evasion of taxes or clearly to reflect the income of any of such organizations, trades, or businesses. The provisions of this section shall apply, but shall not be limited in application, to any case of a common carrier by railroad subject to the Interstate Commerce Act and jointly owned or controlled directly or indirectly by 2 or more common carriers by railroad subject to said Act.
D.C. Code § 47-1810.03