>Be conservative in what you do, be liberal in what you accept from others. ^f7cc48 Author: [[jon-postel|Jon Postel]] in [RFC 793: Transmission Control Protocol](https://www.rfc-editor.org/rfc/rfc793). Note that this makes sense in systems you control, but faced criticism when open to the Internet: [draft-iab-protocol-maintenance-04](https://datatracker.ietf.org/doc/html/draft-iab-protocol-maintenance-04).