Are common knowledge - Idioms by The Free Dictionary
be common knowledge (redirected from are common 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 common/public ˈknowledge be something that everyone knows, especially in a particular community or group: What do you mean you’re surprised he’s leaving? I thought it was common knowledge that he was looking for another job!