Not necessarily germane, but US Naval Officers below the rank of Commander are addressed as "Mr. (last name)". Aboard ship, they are saluted only upon first meeting each day. If you do not use the last name, then you address them by rank. They are of course respected for their position. When addressing the US President, one says "Mr. President", or "President (last name". I would think the proper use of "Mr." to be entirely correct, depending upon one's tone of voice. Stan