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Postel’s Law

Overview

Be liberal in what you accept, and conservative in what you send.

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Key Takeaways

  1. Be empathetic, flexible, and tolerant to any number of actions the user could possibly take. This means accepting variable input from users, translating input to meet the requirements, defining boundaries for input, and providing clear feedback to the user.

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Origins

Postel's Law (also known as the Robustness Principle) was formulated by Jon Postel, an early pioneer of the Internet. The Law is a design guideline for software, specifically in regards to TCP and networks.

Source

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Further Reading

  1. Design Systems and Postel’s Law

    Mark Boulton

  2. Robustness and Least Power

    Adactio

  3. Your Website has Two Faces

    A List Apart

  4. Design with Difficult Data

    Steven Garrity

  5. Robustness Principle

    Wikipedia