Section 902. Pleadings; form

(a)  All  pleadings  shall  be  formal  pleadings, as in supreme court
  practice, except that:
    1. If the plaintiff's cause of action is for money only, the complaint
  may be set forth by indorsement upon the summons. The indorsement  shall
  consist  of  a  statement  of  the  nature and substance of the cause of
  action, and the summons in such instance shall set forth the  amount  in
  which  the  plaintiff will take judgment in the event of default. Unless
  the rules of the court provide otherwise,  the  clerk  shall  make  such
  indorsement for a plaintiff appearing without attorney.
    2.  Where  the  plaintiff's  cause of action is for money only and the
  defendant appears without attorney, he may,  unless  the  rules  provide
  otherwise,  describe  his  answer  to  the  clerk, who shall indorse the
  substance of the answer on, or annex it to, the summons.
    (b) If a formal complaint must be or is used, it shall be served  with
  the  summons,  except  that  if  service is made by publication the CPLR
  shall govern.
    (c) The address of the defendant, and that of his attorney if he shall
  appear by attorney, shall be stated with or in the answer.
    (d) The rules may provide, in actions for  money  only  in  designated
  categories in which the plaintiff might otherwise proceed by indorsement
  as above provided, that a formal complaint, or a formal answer, or both,
  shall be required.
    (e) The court in any case may, at any time before judgment, on its own
  motion  or  on  the  motion on notice of a party, direct the service and
  filing of a formal pleading.