Postel's Law

• General Principle of Robustness (not to be confused with Eric S. Raymond's Rule of Robustness)

• Object-Oriented Design
• API Design

“Be conservative in what you do, be liberal in what you accept from others.”¹⁾

See section contrary principles.

• Fail fast (FF): While FF is (amongst others) about checking for erroneous parameters, Postel's Law is about not being too strict with parameters. It says that the design should allow for uncommon or strangely arranged (yet meaningful) input data. This does not contradict FF as Postel's Law does not demand to process meaningless or erroneous data.

• Principle Of Least Surprise

Stub

• Robustness principle
• Jon Postel: Internet Protocol
• Martin Fowler: Tolerant Reader
• Joel Spolsky: A Hard Drill Makes an Easy Battle
• Eric S. Raymond: The Art of Unix Programming: Rule of Repair

Discuss this wiki article and the principle on the corresponding talk page.