13 Pa.C.S. § 8204: Effect of issuer's restriction on transfer.

A restriction on transfer of a security imposed by the issuer, even if otherwise lawful, is ineffective against a person without knowledge of the restriction unless:

(1) the security is certificated and the restriction is noted conspicuously on the security certificate; or

(2) the security is uncertificated and the registered owner has been notified of the restriction.