208. (1) When any person applies to any officer of Customs for permission to transact any specified business with him on behalf of any other person, such officer may require the applicant to produce a written authority from the person on whose behalf such business is to be transacted, and in default of the production of such authority refuse such permission. (2) The clerk, servant or agent of any person or mercantile firm may transact business generally at the custom-house on behalf of such person or firm: Provided that the appropriate officer may refuse to recognize such clerk, servant or agent unless such person or a member of such firm identifies such clerk, servant or agent to the appropriate officer as empowered to transact such business, and deposits with the said officer an authority in writing duly signed, authorising such clerk, servant or agent to transact such business on behalf of such person or firm.