This sets the loss level at or below which a previously declared signal-degrade condition for this session will be cleared, working as the release valve paired with the set-threshold above it; together they implement hysteresis so a service does not flap rapidly between degraded and clear states if its loss is bouncing right around a single threshold value. Configuring the clear threshold lower than the set threshold, for example set at 10 and clear at 5, means loss has to drop meaningfully below the level that triggered the degrade warning before that warning is lifted, which is the intended behavior per the description's note that these two objects should be configured together.