Robert Grimm pointed out that HTML has an `aside` tag, so that might be a more appropriate semantic markup for marginal notes than `p`. https://www.facebook.com/shriram.krishnamurthi/posts/10162106850905581?comment_id=10162107064895581&reply_comment_id=10162107081285581&comment_tracking=%7B%22tn%22%3A%22R%22%7D