[post_page_title]The buzzer[/post_page_title]
When Queen Elizabeth has her meetings in Buckingham Palace, she doesn’t need to bother with all of these signals, because she has a discreet buzzer to let her staff know when she is ready to finish up.
All the Queen needs to do is push the button, and someone will open the doors to the room and come in to escort her guest out of her presence. Wouldn’t you like to have a buzzer on hand for that purpose?