Yep. It's like if you took a liner lock and put the liner on the opposite side. Instead of having the bottom the tang flat, like in regular liner locks and framelocks, there's a flat back section parallel to, but lower than, the spine of the blade behind the pivot. The liner makes contact there. On top of the liner, which is on top of the tang, is an 'anvil' or stop pin. Downward pressure against the spine of the blade becomes upward pressure against the liner which rests snugly and securely between the tang and the anvil. Doing so makes the strength of the lock come not just from the liner (like in traditional Walker liner locks), but also from the sides of the knife and the stop pin. Also, since the liner is pressed into the anvil, it's much harder to accidentally disengage than a liner lock when twisting the blade while cutting or 'white-knuckle' gripping the handle.
