"In general, an implementation must be conservative in its sending behavior, and liberal in its receiving behavior."

“Remembering Jonathan B. Postel”

“God, at least in the West, is often represented as a man with a flowing beard and sandals... if the Net does have a god, he is probably Jon Postel, a man who matches that description to a T. Mr. Postel's claim to cyber-divinity, besides his appearance, is that he is the chairman and, in effect, the sole member of the Internet Assigned Numbers Authority, the organization that coordinates almost all Internet addresses.”

“In Memory of Jon Postel, Internet Society”

“TCP implementations will follow a general principle of robustness: be conservative in what you do, be liberal in what you accept from others.”

“He worked quietly for years as keeper of the RFCs and final arbiter in technical matters when consensus couldn’t be reached. Postel believed that decisions he had made in the course of his work over the years had been for the good of the community and that starting a company to profit from those activities would have amounted to a violation of public trust.”