It's a technique used in slab homes here in Arizona, where the soil tends to be alternatively wet and dry. In post-tensioning, the concrete slab is made with holes in it and steel cable is run through those holes and then put under great tension before being secured. It keeps the slab in one piece when the soil under it is expanding, contracting, moving, and generally being cranky.
I did some more reading and found that it's a fairly recent technique for homes, mostly used in areas like mine, and I *think* in slab homes, not ones with basements. I don't think it's going to be an issue for you. I should have done the research before mentioning it.
It's post first, think twice, right?
Just like cut first, measure twice.