Section 904. Permissible defendants

The plaintiff, at his election, may
  make defendant in the action:
    1. A tenant by the curtesy or for life or for  years,  of  the  entire
  property, or whoever may be entitled to a contingent or vested remainder
  or  reversion  in  the  entire  property,  or  a person having a lien or
  interest which attaches to the entire property. A  person  specified  in
  this subdivision who is not made a party is not affected by the judgment
  in the action.
    2.  A  person  having  a lien on an undivided share or interest in the
  property. The nature of the lien and the share or interest to  which  it
  attaches shall be specified.
    3. An unknown person entitled to an estate or interest in the property
  sold.  The  court shall provide for the protection of his rights, as far
  as may be, as if he were known and had appeared.
    4. The state.