Swimming backstroke flags are a necessity for any competitive swimming facility to ensure swimmer safety. Rules for swim backstroke flag placement: Permanent provision must be made to anchor backstroke flag lines with minimum sag. At least three pennants must be evenly spaced left, right and center in each lane located 5 yards from each end of a 25-yard racing course [5 meters from each end of a 25- or 50-meter racing course] and approximately 7 feet above the water surface. These pennants should be 6 to 12 inches in width and 12 to 18 inches in length. In any event in which the backstroke is swum, failure to provide these pennants shall result in disqualification of the host competitors. It is recommended that the pennants contrast the ceiling and the remainder of the pool environment to ensure proper safety to the swimmers in the water.