This read-only integer is the upper boundary of the 'HIHI' (high-high, most severe over-range) alarm band for whichever EDFA parameter this table row represents. Network operators compare live readings of that parameter against this ceiling to know the absolute upper limit before the device would flag its worst-case high alarm. For example, if the row tracks output power in tenths of a dBm, a value here might represent the top of the allowed range before a critical high alarm is raised (illustrative, since units are not stated in the source).