11 Pa.C.S. § 127A04
(b) Method of notice.—
(1) If the department proceeds with abatement pursuant to this section, it shall identify the owner of the property by reference to the city's real estate registry if the city maintains a registry or, in the absence of a registry, by reference to county assessment records and shall immediately serve a written notice on the owner by any of the following methods:
(e) Defense.— It shall not be a defense to the determination that a public nuisance exists that the property is boarded up or otherwise enclosed.
Cross References. Section 127A04 is referred to in sections 127A03, 127A05, 127A06, 127A10, 127A11 of this title.