72 Pa. Stat. § 5971g
The county treasurer shall advertise the fact of holding such sale, once a week for three successive weeks prior to the holding of such sale in at least two newspapers of general circulation in the county in which such seated land is located, if there be two newspapers so published; if there be only one, then in such newspaper so published in the county.
Such advertisement shall set forth:
In addition to such advertisement, at least ten days before any such sale, written notice thereof shall be served by the county treasurer, by registered mail or certified mail, upon the owner of such land, and if the whereabouts of the owner is unknown, such notice shall be served by registered mail or certified mail upon the terre tenant, if any. In the case of a mobilehome or house trailer subject to real property tax, a copy of such notice shall at the same time and in like manner be sent to the encumbrance holders of record. If such notice cannot be served in said manner on the owner or terre tenant, then such notice shall be served by the county treasurer by posting the same in the courthouse and at a conspicuous place on the premises. If notice was mailed as herein required, no such sale shall be prejudiced or defeated, and no title to property sold at such sale shall be invalidated by proof that such written notice was not received by the owner or terre tenant as herein provided.
The cost of such advertisements, notices and the service thereof shall be taxed as part of the cost of such proceedings and shall be paid the same as the other costs.
72 P.S. § 5971g