See also Thomas Schelling, and many other engineering and economics papers I haven’t heard of yet. Minimum power principle. Economics of standards. Partial contracts. Power outlets. Peyton Young on which side of the road you drive on.
[…] this is where Jon Postel caused a problem, back in 1981, when he coined the robustness principle: “Be conservative in what you do, be liberal in what you accept from others.”
[…] Postel’s “robustness” principle didn’t really work. The problem wasn’t noticed for many years. In 2001 Marshall Rose finally wrote:Counter-intuitively, Postel’s robustness principle […] often leads to deployment problems. Why? When a new implementation is initially fielded, it is likely that it will encounter only a subset of existing implementations. If those implementations follow the robustness principle, then errors in the new implementation will likely go undetected. The new implementation then sees some, but not widespread deployment. This process repeats for several new implementations. Eventually, the not-quite-correct implementations run into other implementations that are less liberal than the initial set of implementations. The reader should be able to figure out what happens next.