Rule #88: Bar Stool Etiquette
Bar stools are valuable real estate. You have a right to protect them. If a customer sits down and wants to save a seat for a friend let him, as long as the friend is expected soon and the bar isn't three deep. However, if the customer tries to save stools for more than one friend, and it's busy, tell him that your restaurant has a first come, first serve policy. If the customer looks desperate or irritated, tell him that you'll keep his friends in mind and will help them get a spot once they arrive.