Given the fact that prohibition signage often includes the universal prohibition symbol, it does a great job at drawing attention and communicating the prohibited action with a rather limited scope of ambiguity. A case in point is the current Covid-19 pandemic, for which even the CDC recommends the use of signs that discourage certain actions such as handshakes, crowding, sharing, etc., particularly during community events and gatherings that involve interaction with people not part of one’s household.