 It is one of several April Fools' Day Request for Comments.Waitzman described an improvement of his protocol in RFC 2549, "IP over Avian Carriers with Quality of Service" (1 April 1999).Later, in RFC 6214—released on 1 April 2011, and 13 years after the introduction of IPv6—Brian Carpenter and Robert Hinden published "Adaptation of RFC 1149 for IPv6".