Producers of the new Broadway revival of William Shakespeare's Macbeth, starring Tony Award winner Alan Cumming, aren't taking the alleged curse of the supernatural tragedy lightly. For over five centuries, saying the "M-word" in or around a theater has been known to unleash disasters upon a production, from forgotten props to lost lines to matters even worse, including actor illness and the occasional death. (It's speculated that one of the reasons for the play's curse is that Shakespeare used actual incantations for the words of the three Weird Sisters.)
Ken Davenport and company have wisely spared audience members the trouble of elaborate cleansing rituals (like leaving the theater, turning around three times, spitting over one's shoulder, reciting a different Shakespeare verse, knocking to get back in, and so on) by posting the above sign on all doors of the Ethel Barrymore Theatre. This way, you can watch Cumming's solo take on the drama without fear of repercussions.
So don't say M-word. You've been warned.