That's basically adjusting what you do to what will happen. Kinda hard to explain, so let me give you an example. You have everything set up perfectly, but as you tighten the locknut, the axle backs the cone off 1/4 turn. So what you do is get everything perfect, then tighten up the cone 1/4 turn, then as you tighten down the lock nut, the alxe backs off its 1/4 turn and its now set perfectly. Of course its not that easy because if you tighten down the cone all the way, the alxe might not move the full 1/4 back. So you gotta play around till you get the right combination.