Explain the following article:

1501(own explanation and example)

• Quasi-traditio
• Delivery by agreement signifying a transfer of possession

1502

• Contracts of sale or return, and of sale on trial or approval or statisfaction
• sale or return distinguished from sale on trial

1503

• Delivery of specific goods sold generally passes title
• Reservation of right possession or ownership when specific goods are shipped
• where seller of his agent is consignee
• where seller's title only purpose of security
• where buyer or his agent is consignee but seller retains the bill of lading
• where bill of lading is sent forward with draft attached

reference: https://www.academia.edu/30200885/LAW_ON_SALES