what the rules specifically say are that you must ensure that your statio operates according to the rules and it leaves it up to you how to do it. for example if you know you can assure legal operation you can be across the room or on the other side of the house as long as you are willing to trust your license to the legal operation of your station. back before I got my license my elmer would just let me operate with his call sign because he knew I would follow the rules he set down for me. same goes for my girlfriend I will let her work hf and I know she will follow the rules, so I can gt a drink or do something else while she is operating.