Locking pins and clips are an essential requirement for all pallet racking beams. You should always have at least two clips per beam, one for each connector on either end of the beam.
The pin is inserted into the beam and then into the racking frame upright face securing the the two together.
If the pin is not in place, there is a chance that a fork lift truck could dislodge the beam when handling pallets and then cause a severe accident and damage to both the pallet racking and any pedestrians nearby.