How much force is the securement system required to withstand in terms of cargo weight?

A 80% forward, 50% rearward, 50% sideways, 20% upwards.

explanation

How strong must the vehicle structure and anchor points be?
All elements of the vehicle structure and anchor points must be strong enough to withstand the forces described on page 7.
Forward force: 0.8 g (80%)
Rearward force: 0.5.g (50%)
Sideways force: 0.5 g (50%)
Upward force: 0.2 g (20%).