iI took a cruise on caribbean princess nov.13-20. Each morning my husband and I ordered the room service breakfast and ate on the balcony. I was not fully aware of the tipping protocol. When the delivery person handed me the slip to sign, I signed my name , the time of delivery, and the 2 $ I was giving as a tip. I also paid the person the 2$ in cash. I figured the signing of the 2$ was just as a record for the delivery person to take back to the manager. As I found out at the end of the cruise, my account was also charged 2$ each morning . So each room service cost me 4$ instead of 2$. I will never sign the gratuity slip again for any amt.--I learned the hard/expensive way!