Where do I need double hose clamps in my fuel system?

There is some confusion out in the field over where double clamping is required in fuel system installations. The photo above illustrates the issue. In the photo you clearly see double hose clamps employed on a fuel line attached to the fuel filter. The potential problem with this installation is that the hose barb protruding from the filter housing may not have enough length to support the two clamps. Simply the second clamp out away from the housing may only be clamping on the hose either ...