(a) For the purpose of this section- (1) "agency" has the meaning given it by section 551 of this title; and (2) "State" means a State, a territory or possession of the United States including a Commonwealth, or the District of Columbia. (b) An individual who is a member in good standing of the bar of the highest court of a State may represent a person before an agency on filing with the agency a written declaration that he is currently qualified as provided by this subsection and is authorized to