Two runners may not occupy a base, but if, while the ball is alive, two runners are touching the same base, the following runner shall be out when tagged.
When a pitcher is contacting the pitcher’s plate and in possession of the ball, runners shall not leave their bases until the ball has been delivered and reached the batter.
That foul territory is considered the part of the playing field outside the first and third base lines extended to the fence and perpendicularly upwards.
Any runner is out when the runner fails to keep contact with the base to which that runner is entitled until the ball has been released by the pitcher on the delivery.