P.R. Laws tit. 19, § 555
(a) If an indorsement is made by the holder of an instrument, whether payable to an identified person or payable to bearer, and the indorsement identifies a person to whom it makes the instrument payable, it is a “special indorsement.” When specially indorsed, an instrument becomes payable to the identified person and may be negotiated only by the indorsement of that person. The principles stated in § 510 of this title apply to special indorsements.
(b) If an indorsement is made by the holder of an instrument and it is not a special indorsement, it is a “blank indorsement.” When indorsed in blank, an instrument becomes payable to bearer and may be negotiated by transfer of possession alone until specially indorsed.
(c) The holder may convert a blank indorsement that consists only of a signature into a special indorsement by writing, above the signature of the indorser, words identifying the person to whom the instrument is made payable.
(d) Anomalous indorsement. — Means an indorsement made by a person who is not the holder of the instrument. An anomalous indorsement does not affect the manner in which the instrument may be negotiated.
History —Aug. 17, 1995, No. 208, § 2-205; Aug. 31, 1996, No. 176, § 2.