D.C. Code § 47-3309

In any matter affecting taxation, the determination of which is by law left to the discretion of the Mayor, the Mayor may, if he so elects, refer such matter to the Superior Court to make findings of fact and submit recommendations, such findings of fact and recommendations, if any, to be advisory only and not binding on the Mayor, and shall be without prejudice to the Mayor to make such further and other inquiry and investigation concerning such matter as he in his discretion shall consider necessary or advisable.