Abstract: A locator stop (10) having a body (12) is arranged to be supported on an upper surface of a truss table formed with a plurality of panels (P), so as to extend across a slot (S) between successive panels. The body (12) has a basal surface (22) by which it is supportable on the upper surface of the table. The stop has a lock (14) which projects below the body (12) so as to be at least partly locatable in the slot (S). The lock (14) has dimensions in two mutually perpendicular directions, substantially parallel to the basal surface (22), which respectively are less than the width of the slot (S) and greater than the width of the slot. The lock (14) is adjustable by a manual operation performed above the table, wherein the lock (14) is able to firmly engage at least one of the panels (P) defining the slot (S) and thereby clamp or hold the body (12) on the upper surface at a required position along the slot.