In carpentry, what do you call this kind of support?
In my attic, laying across ceiling joists (perpendicular to them) is a 2x6. The flat 2x6 is nailed into the top of each joist. Then there is another 2x6 on edge adjacent to that first-described 2x6 and nailed through its flat surface into the edge of the first-described 2x6 to form an "ell". So along its length, these two pieces of 2x6 have great strength, and they lend that strength (I suppose) for lateral support to the joists to which it is nailed.
I keep thinking it is called a saddleback, but I can't find anything to support that in my searches. Anybody know?