Well I have always wrote something in, and its almost always taken off at checkout, but I have gotten some random charges. I just checked my recept from HR Indy and for a $13.04 breakfast buffet, I got charged $.26, I belive I put $2.96 as tip, which put the percentage they would cover @ 20%

Since it seems like this is a popular topic for different hotels, I shall add this into my database im creating!