Many large meshes are decomposed into smaller meshes called domains that, when added together, make up the whole mesh. Each domain typically has its own range of cell numbers that begin at 0 or 1, depending on the mesh's cell origin. Any global cell numbering scheme that may have been in place before the original mesh was decomposed into domains is often lost. However, some meshes have auxiliary information that allows VisIt to use the original global node and cell numbers for the domains. If you want the pick output to contain global node and cell numbers if they are available, click on the Display global nodes/zones check box.