53 Pa. Stat. § 7111
This act shall apply only to claims wherein the right to file a lien accrues after the date of its passage, and to tax claims for the years one thousand nine hundred and twenty-one, one thousand nine hundred and twenty-two, and one thousand nine hundred and twenty-three, and to municipal claims heretofore lawfully imposed or assessed within six months before the passage of this act and not liened at the time of its passage; but the rights of other claimants, under existing laws, shall remain unaffected by its passage, and all claims properly filed thereunder are hereby validated: Provided, however, That all tax and municipal claims filed under any prior act of Assembly, or directed to be filed under any such prior act or acts, including the act, approved the fourth day of June, one thousand nine hundred and one (Pamphlet Laws, three hundred and sixty-four), may hereafter be revived, continued, and collected under and according to the procedure and provisions of this act.
53 P.S. § 7111