Here, its known as "Comair Standard". Our contract gives us 11 days off, a group of 3 hard days and a group of 4 hard days, along with 4 movable soft days.
The norm here seems to be: 6 on, 1 off, 6 on, 3 off, 3 on, 4 off, 3 on, 1 off, 2 on, 2 off (or something close).
The best ones are when your last two weeks of a month are 6 on-1 off-6 on, then your next month starts with 6 0n-1 off-6 on!
Oh well, 800-900 of us won't have to worry about it much longer, I guess