pigs can fly

Internet community have its own way to enforce rules, as opposed to existence of a "Parliament".
Everyone may have a Request For Comment (RFC). As long as the community comments converged the RFCs become "standards", which is still a RFC.
Sometimes RFCs are standard "de facto".
One of them is The Twelve Networking Truths
Below is the third of these Truths:
With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead.