This Gauge32 holds the highest single-sample count of unexpected PCIe completions that UCS Manager observed during any one collection interval within the last day, i.e. the adapter received a completion TLP that did not match any outstanding request it had issued, captured at its worst moment. Unlike the plain (non-H) gauge for this window, this high-water value stays latched at the worst reading for the rest of the window even if the fault stops recurring, which is what lets an admin catch a brief PCIe error burst that a simple end-of-window snapshot would have missed. For example, if a marginal riser produced a spike of 11 unexpected PCIe completions in one polling cycle and then went quiet, this field would hold 11 until the last day window rolls forward, even though the plain gauge has since dropped to 0.