Does the following sentence require a period or a question mark at the end?
"Could you please call me when you have a moment" I think it needs a question mark because it's posed as an interrogative, a friend of mine says that it's a polite command/request and should end in a period. I think if it were a polite command it would simply state "Please call me when you have a moment." but when adding "could" I think it should be considered a question, but maybe it's a matter of style. What do you think?