COM §8304: (a) An endorsement may be in blank or special.

(a) An endorsement may be in blank or special. An endorsement in blank includes an endorsement to bearer. A special endorsement specifies to whom a security is to be transferred or who has power to transfer it. A holder may convert a blank endorsement to a special endorsement. (b) An endorsement purporting to be only of part of a security certificate representing units intended by the issuer to be separately transferable is effective to the extent of the endorsement. (c) An endorsement, whether special or in blank, does not constitute a transfer until delivery of the certificate on which it appears or, if the endorsement is on a separate document, until delivery of both the document and the certificate. (d) If a security certificate in registered form has been delivered to a purchaser without a necessary endorsement, the purchaser may become a protected purchaser only when the endorsement is supplied. However, against a transferor, a transfer is complete upon delivery and the purchaser has a specifically enforceable right to have any necessary endorsement supplied. (e) An endorsement of a security certificate in bearer form may give notice of an adverse claim to the certificate, but it does not otherwise affect a right to registration that the holder possesses. (f) Unless otherwise agreed, a person making an endorsement assumes only the obligations provided in Section 8108 and not an obligation that the security will be honored by the issuer.