I never knew what this was until today. But just a week ago, I was looking for ORD-ATH award flights and no saver available, I had a non status friend, that booked a saver award after asking for a supervisor several times. He got ord-fra-ath both ways on a saver. I didn't believe him as the same day, I called and nada.
He does spend over 100K on the United Mileage Card.