Standing the container on supports is also not that simple, since the ISO test requires that records are made of any plastic or permanent deflection. Since the test criteria (ISO Technical Report (TR) 15070 Series 1 freight containers — Rationale for structural test criteria) requires measurement of residual deformation production tests need to be on a pad that facilitates access to the underside out of the unit. However, the values in these criteria only confirm the ability of the under structure to support a fork truck; they do not confirm that the flooring material is suitable. For this to be verified the floor panels need to be removed after testing to check for signs of cracking or internal delamination especially near the middle of the plies.