Section 322. Authority for appearance of attorney in real property action

(a) Authority of plaintiff's attorney. Where the  defendant  in
  an  action  affecting real property has not been served with evidence of
  the authority of the plaintiff's attorney to begin the  action,  he  may
  move  at any time before answering for an order directing the production
  of such evidence. Any writing by the plaintiff or his  agent  requesting
  the  attorney to begin the action or ratifying his conduct of the action
  on behalf of the plaintiff is prima facie  evidence  of  the  attorney's
  authority.
    (b) Authority of non-resident defendant's attorney. The attorney for a
  non-resident  defendant  in an action affecting real property shall file
  with the clerk  written  authority  for  his  appearance,  executed  and
  acknowledged  in the form required to entitle a deed to be recorded, and
  shall serve either a copy of such authority or notice of such filing  on
  the  plaintiff's attorney within twenty days after appearing or making a
  motion.
    (c) Agencies or wholly-owned corporations of the United States.   This
  rule  does  not apply to an attorney representing an official, agency or
  instrumentality of, or corporation wholly owned by, the United States.