"No props, notes, charts, diagrams or other writings can be used by the candidates; however, they can take notes on the type of paper of their choosing.The candidates cannot ask each other direct questions, but can ask rhetorical questions.The candidates cannot address each other with proposed pledges.Each candidate can use his own makeup artist.No candidate is allowed to use risers or any other device to make them look taller.The Coin Toss: At least 72 hours before the first debate, there will be a coin toss on the order of questioning and closing arguments."

– Debate Rules

UPDATE: Romney campaign says it was a handkerchief.