Section 1909. Rights of the parties to be determined; unknowns 1

Where an order is made directing the sale of the real property for
  distribution  or  directing  the  transfer  thereof  to  a   spouse   or
  beneficiary  the court may fix and determine the rights and interests of
  the respective parties in the order, or may postpone  the  determination
  until the final judicial settlement of the accounts of the fiduciary.
    2.  If  a  party  entitled to an estate or interest in the property is
  made a party as  a  person  unknown  the  court  must  provide  for  the
  protection  of his rights, as far as may be, as if he were known and had
  appeared.