Is anyone aware of any State law that governs information that is required on a signature card?

Off the top of my head, you might try looking in 7 P.S. 600 et seq. Depending on whether you have contract language in your card or in a seperate doc, you need to be aware of the disclosure requirement for NOWs for banks & savings banks in 10 Pa. Code 30.2. Also try looking at 10 Pa. Code 33 & 34 for S&L info.