More and more riders extend filling material used inside the hoof to the backside of the hoof, suggesting that this gives better protection. However, filling material is only allowed inside the hoof (FIPO 2.3.7), basically in the area between a sole and the hoof. When protective material is used otherwise, the understanding of FIPO is that the material can be taken off in order to determine the weight. This is not the case with material that is glued to the hoof as it adds more (uncontrollable) weight to the hoof.