P.R. Laws tit. 10, § 427
A negotiable receipt may be negotiated by delivery:
(a) Where, by the terms of the receipt, the warehouseman undertakes to deliver the goods to the bearer, or
(b) where, by the terms of the receipt, the warehouseman undertakes to deliver the goods to the order of a specified person, and such person or a subsequent indorsee of the receipt has indorsed it in blank or to bearer.
Where, by the terms of a negotiable receipt, the goods are deliverable to bearer or where a negotiable receipt has been indorsed in blank or to bearer, any holder may indorse the same to himself or to any other specified person, and in such case the receipt shall thereafter be negotiated only by the indorsement of such indorsee.
History —Feb. 21, 1918, No. 9, p. 22, § 37.