Avis de réception (English: Advice or acknowledgment of receipt) is a postal service returning to the sender a form or card signed by the recipient. This is evidence that the letter was received, and these forms (or cards) are frequently seen with legal endorsements. It had existed under various names in some postal entities as early as the late 18th century, and was adopted by the GPU General Postal Union in 1875, and again by its successor, the UPU Universal Postal Union in 1879.