In a text I'm writing a thick broken rule appeared. I've tried to delete it, but it doesn't go away. If I delete it in one place, it pops up at the bottom of the next paragraph. What is it, and how can I get rid of it? I'm guessing that I may have accidentally hit some key combination, or perhaps copied and pasted something from elsewhere, that forces a broken rule, but I can't see what it is or how to get rid of it. Thanks to anyone who can help with this.