P.R. Laws tit. 10, § 432
A person to whom a receipt has been transferred but not negotiated, acquires thereby, as against the transferor, the title of the goods, subject to the terms of any agreement with the transferor.
If the receipt is nonnegotiable such person also acquires the right to notify the warehouseman of the transfer to him of such receipt, and thereby to acquire the direct obligation of the warehouseman to hold possession of the goods for him according to the terms of the receipt.
Prior to the notification of the warehouseman by the transferor or transferee of a nonnegotiable receipt, the title of the transferee to the goods and the right to acquire the obligation of the warehouseman may be defeated by the levy of an attachment or execution upon the goods by a creditor of the transferor, or by a notification to the warehouseman by the transferor or a subsequent purchaser from the transferor of a subsequent sale of the goods by the transferor.
History —Feb. 21, 1918, No. 9, p. 22, § 42.