be common/public knowledge
be common knowledge
To be something that is generally or widely known, whether or not it has been verified or officially recognized. The fact that a healthy diet and regular exercise are the best defense against disease is common knowledge at this point.
be public knowledge
To be information that is available to anyone (the public) or that is generally or widely known. These reports will all be public knowledge after the trial is over, but for now they must remain secret.