It's commonly known, which, at least in the context of Game Theory, is different from "common knowledge". (At least in Game Theory, common knowledge means that

It's commonly known, which, at least in the context of Game Theory, is different from "common knowledge". (At least in Game Theory, common knowledge means that everyone knows, and everyone knows that everyone knows, and everyone knows that everyone knows that everyone knows... until you reach the bottom of infinite recursion... and then the usual infinite stack of turtles.)