Omega event
An event that requires an exception to the rules. Thought to always be possible, no matter how encompassing the rules are. Coined by @Yishan (Twitter) who credited Erik Martin, one of Reddit's first community managers, with the concept.
We have become so accustomed to the notion of “free speech, except” that we do not realize that free speech is ALWAYS limited, and that every limit arose from an Omega Event. - Yishan