They are referring to bump steer. As the suspension moves up (bump), The arc of the control arm moves the lower pickup point(balljoint) inboard. this affects toe-in as that happens. The remedy is a spacer between balljoint to steering knuckle. In effect this puts the control arm at the max of it's arc which minimizes how much camber/toe change on bumps. Also the tie rods act the same way and need to be parrallel to the control arms. IT class doesn't allow ball joint spacers, but they might have recently allowed tie rod end adjustments... Check the GCR and Fastrack.