Postel's Law

Also known as the Robustness Principle, Postel's Law states that we should be "conservative in what you do, be liberal in what you accept from others." This principle was originally applied to TCP/IP, but it has been widely adopted in software development and design.

In the context of design, Postel's Law means:

• Be liberal in what you accept: Design systems that are tolerant of a wide range of user inputs and actions. Anticipate that users will make mistakes and provide input in unexpected formats. The system should be flexible enough to handle this variability.
• Be conservative in what you do: The system's output should be consistent, well-structured, and predictable. This ensures that other systems (and users) can reliably interpret and interact with it.

By following this principle, we can create more resilient and user-friendly systems. It encourages empathy for the user and leads to designs that are more forgiving of errors and more adaptable to different user behaviors.