Buck. Cnty. Pa. 3129*(f)
Notice of the sale of real property, specifying the matters and things required to be contained in the notice provided by Pa.R.C.P. 3129(a) and (c), shall also be given in writing by the plaintiff or some person on his behalf, by personal service on, or by certified mail, to the defendant in the writ and to the real owner or owners of the real property to be sold, at least 10 days prior to the sale. An affidavit of service shall be filed with the prothonotary, before the date of the sale, setting forth that the notice so required has been given in accordance therewith, or that the notice cannot be given because the plaintiff and the person acting on his behalf do not know and have not been able to ascertain the real owner or owners of said real property, or their addresses, or the names or addresses of some of them, or the whereabouts of the defendant in the writ, in which case such an affidavit shall be in compliance with this rule as to the real owner or owners whose names or addresses are unknown, or as to the defendant in the writ whose whereabouts are unknown.
Buck. Cnty. Pa. 3129*(f)