Vampyr, on 2016-August-30, 11:00, said:
Played someone recently whose 1NT range was 11-17. I wish I'd had time to find out what the follow-ups were. And the sequences they were gaining with whatever they used a 1NT rebid for.
When we played 11-16, we played a 17-19 1N rebid which got the occasional gain when other people were playing 2N.