permissive

“For neither Man nor Angel can discern / Hypocrisy, the only evil that walks / Invisible, except to God alone, / By his permissive will, through Heaven and Earth;”

“"Permissive" working allows more than one train to be in a block section at one time but trains must be run at low speed in order to stop on sight behind the train in front. Such working is often authorised to allow freight trains to "bunch" together to await a path through a bottleneck instead of being strung out over several block sections, as would be necessary if absolute working were in force.”

“Many permissive paths work well and have done for a significant amount of time, enhancing or connecting our network of public footpaths, byways and bridleways, however unevenly distributed.”