To supersede the requirements of Sentence 4.6.5.1.(2) and permit slightly longer lengths of hose if certain measures are taken [e.g. retractable mechanisms] to limit the amount of hose length exposed to the hazards identified in the analysis of Sentence 4.6.5.1.(2).
This is to limit the probability of an unwanted escape of liquid from the hose, which could lead to the ignition of vapour from a nearby ignition source, which could lead to damage to the building or facility.